AVIRA

Avira's AntiVir has been a player in the security world for some time; however, in 2008 its status boomed because of its remarkably strong detection rates. It still remains near the top of independent antivirus efficacy tests, but while the 2009 version more or less kept pace with the competition, the 2010 edition isn't quite as good as it could be.
Both longtime and new users alike will note the pop-up ad that appears whenever a program update is downloading; it has been the unaddressed focus of critical and user dislike for several years. While the occasional ad that interferes with a user's work flow used to be considered tolerable for effective free security, that's no longer the case. Avira's lack of a silent-running entertainment-gaming mode is also noticeable, since so many free and paid competitors now offer the mode.
Except for the most cosmetic of changes, the app's interface is unchanged from version 8. There are new icons on the program's toolbar, a new static image background, and that's about it. The main window offers a left-side navigation menu with drop-down menus and a central pane to see more detailed information. AntiVir opens to the Status menu, informing you of your last scan, your last definition file update, whether the real-time guard is active; however, Avira removed the premium upgrade link in this version. The Events screen logs changes to the program and the Reports tab keeps a history of threats--information from both sections can be exported.

New features are a bit thin in the free version of Avira 10, too. A new generic-repair mode really just takes the choice out of how Avira tells you about the threats it has discovered. In version 9, you could be informed about them in the middle of a scan or at the end; however, now only the latter is available. Windows 7 users now have the capability to run a scan as an administrator directly from the interface, which is a smart, but minor improvement. Avira's installation sequence has been revamped, and now only takes users through five windows. Theoretically, this means it's a five-click installation, but new users will have to complete the registration form. However, its installation file unpacking process appears faster, and you no longer have to reboot after the install.
This isn't to say that AntiVir Free 10 isn't stuffed with robust features. The program offers a wide selection of scan customization, letting users fully scan both internal and external hard drives, run a preloaded scan--for rootkits, for example--or customize a scan. On a real-world computer, the full scan took about 1 hour and 12 minutes, which is average. Avira includes antispyware protections, scanning tech that can crack open "locked" files, improved internal security to prevent AntiVir's files from being maliciously altered, and one-click threat removal--baby-sitting was taken out in the last version.
The Local Protection and Administration navigation options reveal the Scanner, Guard, Quarantine, and Scheduler features. Combined with the Configuration button located at the top of the central pane, users can customize scans as necessary. When Avira quarantines a file, its information is on display along with options to scan it again, restore, delete, and e-mail the file to Avira. The apps rebuilt heuristic engine retains the same choices from the previous version had, and it can be turned on or off in part or in full and offers three intensity levels. Not counting the lively user forums, Avira's included help features are good for a free antivirus app, with mouse-over information on each feature. The scheduler, once a major Avira selling point because it was light-years ahead of other free security suites, has now been caught up to by its competitors.

Avast

Avast! Free Antivirus is perfect for people who send e-mails and surf popular websites. avast! is a package of applications that aim to protect your computer from a possible virus infection or other malware threat. If you use it correctly, and in combination with other programs such as data backup utilities, it will significantly reduce the risk of your computer being attacked or infected by a virus, and thus the risk of losing important or private data.

Based on the award-winning avast! antivirus engine, avast! antivirus contains all of the features you would expect in a modern antivirus program. It incorporates anti-spyware technology certified by West Coast Labs' Checkmark process, as well as anti-rootkit and strong self-protection capabilities, but now provides even faster scanning with improved detection ability. It contains several real-time "Shields" which continuously monitor your email and internet connections and check the files on your computer whenever they are opened or closed.

avast! antivirus now also comes with a completely revamped user interface for easier scanning. offers a number of additional features, including a script shield and a process virtualization module, while  comes with an antispam filter and built-in firewall. Once installed, avast! runs silently in the background to protect your computer against all known forms of malware. You don't need to do anything else - just install and forget!

NOTE: Free only for personal and non-commercial use.

Core and detection:
· Antivirus and anti-spyware engine
· State of the art scanning engine provides reliable protection against viruses, spyware and other forms of malicious software.

Real time anti-rootkit protection:
· Unique "on access" technology checks all kernel-mode drivers that the operating system is loading for signs of rootkit behavior. This enables even unknown rootkits to be detected and stopped before they can do any damage.

avast! Community IQ:
· Most samples we process come from sensors deployed throughout the avast! community in the Behavior shield and anti-rootkit modules. This is a unique source of data made possible only thanks to our huge user base. Most of the collected samples are analysed by a number of automated processes and only a small fraction of the samples need to be processed manually by our virus analysts.

Code emulator:
· When a suspicious executable is encountered (during both on-demand and on-access scanning), avast! is able to emulate the program’s code in an isolated environment. The code emulator is used for two purposes. First, it is used for generic unpacking. Secondly, it is used in the heuristics engine. Technically, this is done using dynamic translation, a method much faster than traditional emulation techniques.

Heuristics engine:
· avast! features a new heuristics engine designed to proactively detect malware undetectable with normal definitions. The heuristics engine is able to cover both binary (executable) and script malware.


Potentially unwanted programs detection:
· avast! detects potentially unwanted programs, such as remote admin tools and commercial key loggers. Custom rules can be set for dealing with these types of programs.

Scanning:
· Boot-time scanner
· Allows you to scan your computer for infections before the operating system has started and before a virus can be activated (32-bit operating systems only).

Command-line scanner:
· Enables you to run a scan directly from the command line.

Wake-up for scan:
· Microsoft Windows is woken from sleep or hibernation mode, performs a scheduled scan, then returns back to sleep mode.

Scheduled scanning:
· Allows users to define the scan time and files to be scanned.

avast! Intelligent Scanner:
· Can reduce the number of required file scans by up to 80% through a white list of proven safe applications. Files identified as safe are not rescanned unless they change.

Shields:
· Behavior Shield
· Monitors activity on your computer using a number of sensors (file system, registry and network based) and reports/blocks any suspicious behavior.

· Behavioral Honeypots
· avast! sensors identify and monitor suspicious file activity on selected computers, automatically submitting files to the Virus Lab for additional analysis.

· File System Shield
· Real-time scanning of opened/executed files.

· Mail Shield
· Scans all incoming/outgoing e-mails for malware. For MS Outlook, a special plug-in is used. Other email clients are protected by a generic POP3/IMAP4/SMTP proxy. New in version 5, the proxy also supports scanning of SSL communication (gmail.com, sympatico.ca, ….)

· Web Shield
· Scans all visited web pages and checks all files, pages and java scripts downloaded from the internet. Thanks to the Intelligent Stream Scan feature, the Web shield doesn't slow down your web browsing.

· P2P Shield
· Checks files downloaded using P2P programs. - ABC, Ares, Azureus, BearShare, Bit Torrent, BitComet, BitLord, BitPump, CZDC++, Direct Connect, eDonkey, eMule, iDC++, iMesh, Kazaa, Kceasy, LimeWire, Morpheus, Opera's DC++, Overnet, Qtrax, Shareaza, SoulSeek, StrongDC++, uTorrent, Vuze, WinMX, Winny2, Zultrax.

· IM Shield
· Checks files downloaded while using instant messaging or “chat” programs. - AIM (AOL Instant Messenger), Gadu-Gadu, gaim/Pidgin, Google Talk, ICQ, IM2 Messenger, Infium, Miranda, mIRC, MSN/Windows Messenger, Odigo, PalTalk Messenger, Psi Jabber Client, QIP, QQ, SIM, Skype, Tlen, Trillian, WengoPhone, XFire, Yahoo! Messenger.

· Network Shield
· Provides protection against network-based viruses. The module has two main components: a URL blocker, designed to block malicious URLs (as defined by the Virus Lab), and a lightweight intrusion-detection system.

Updates:
· Smart virus definition updates
· Incremental updating system minimizes the size of regular update files.

· Fast application of updates
· New format for the virus definition file speeds up application of updates into avast! 5.0 and reduces demand on CPU/memory, resulting in uninterrupted computer use.
· New format for the virus definition file means faster updates and reduces demand on CPU/memory, resulting in uninterrupted computer use.

Gaming:
· New Silent/Gaming Mode automatically detects full-screen applications and disables pop-ups and other on-screen notifications without degrading security.

Optimized for latest Intel Core i7 CPUs:
· Critical sections of the avast! scanning engine code have been optimized to deliver unrivaled performance on the latest Intel chips.

CPU optimization:
· Multi-threaded scanning optimization
· avast! runs faster on new multi-core CPUs. A new avast! feature allows the splitting of large individual files between cores, accelerating the scanning process.

Green computing:
· Reduced demands on the disk drive result in lower energy consumption.

Miscellaneous:
· avast! iTrack - Real-time graphic scanning reports.
· Graphical user interface - Easy to navigate graphical interface.
· Automatic processing - Infected files are processed automatically without requiring user instructions.
Requirements:

· Processor Pentium 3
· 128 MB RAM
· 100 MB of free hard disk space
What's New in This Release:

· New Script Shield - now scanning deeper and supporting more host processes
· Web Shield now scanning all processes by default
· Stability improvements in aswSP.sys
· Better tracking of file sources
· WebRep now working in new versions of Firefox
· Under-the-hood improvements in the Behavior Shield and Sandbox modules
· Solved a compatibility problem with certain Steam-based games
· Minor improvements in the product UI
· Various other security and stability related fixes

Reasons why this program is marked as ad-supported:

· Offers to download or install software or components (Google Chrome) that the program does not require to fully function

Hard Disk

Hard Disk Details

Technical Details:
This section attempts to give you enough basic information about your hard disks and the disk booting process so that you can troubleshoot most problems you might encounter when getting set up to boot several operating systems. It starts in pretty basic terms, so you may want to skim down in this section until it begins to look unfamiliar and then start reading.

Disk Primer

Three fundamental terms are used to describe the location of data on your hard disk: Cylinders, Heads, and Sectors. It is not particularly important to know what these terms relate to except to know that, together, they identify where data is physically on your disk.
Your disk has a particular number of cylinders, number of heads, and number of sectors per cylinder-head (a cylinder-head also known now as a track). Collectively this information defines the “physical disk geometry” for your hard disk. There are typically 512 bytes per sector, and 63 sectors per track, with the number of cylinders and heads varying widely from disk to disk. Thus you can figure the number of bytes of data that will fit on your own disk by calculating:

(# of cylinders) × (# heads) × (63 sectors/track) × (512 bytes/sect)

For example, on my 1.6 Gig Western Digital AC31600 EIDE hard disk, that is:

(3148 cyl) × (16 heads) × (63 sectors/track) × (512 bytes/sect)

which is 1,624,670,208 bytes, or around 1.6 Gig.

The Booting Process

On the first sector of your disk (Cyl 0, Head 0, Sector 1) lives the Master Boot Record (MBR). It contains a map of your disk. It identifies up to 4 partitions, each of which is a contiguous chunk of that disk. FreeBSD calls partitions slices to avoid confusion with its own partitions, but we will not do that here. Each partition can contain its own operating system.

Table 1. Partition IDs

ID (hex)	Description
01	Primary DOS12 (12-bit FAT)
04	Primary DOS16 (16-bit FAT)
05	Extended DOS
06	Primary big DOS (> 32MB)
0A	OS/2®
83	Linux (EXT2FS)
A5	FreeBSD, NetBSD, 386BSD (UFS)

The dreaded 1024 cylinder limit and how BIOS LBA helps

The first part of the booting process is all done through the BIOS, (if that is a new term to you, the BIOS is a software chip on your system motherboard which provides startup code for your computer). As such, this first part of the process is subject to the limitations of the BIOS interface.
The BIOS interface used to read the hard disk during this period (INT 13H, Subfunction 2) allocates 10 bits to the Cylinder Number, 8 bits to the Head Number, and 6 bits to the Sector Number. This restricts users of this interface (i.e. boot managers hooked into your disk's MBR as well as OS loaders hooked into the Boot Sectors) to the following limits:

• 1024 cylinders, max
  
• 256 heads, max
  
• 64 sectors/track, max (actually 63, 0 is not available)
  
  

Now big hard disks have lots of cylinders but not a lot of heads, so invariably with big hard disks the number of cylinders is greater than 1024. Given this and the BIOS interface as is, you can not boot off just anywhere on your hard disk. The boot code (the boot manager and the OS loader hooked into all bootable partitions' Boot Sectors) has to reside below cylinder 1024. In fact, if your hard disk is typical and has 16 heads, this equates to:

1024 cyl/disk × 16 heads/disk × 63 sect/(cyl-head) × 512 bytes/sector

which is around the often-mentioned 528MB limit.
This is where BIOS LBA (Logical Block Addressing) comes in. BIOS LBA gives the user of the BIOS API calls access to physical cylinders above 1024 though the BIOS interfaces by redefining a cylinder. That is, it remaps your cylinders and heads, making it appear through the BIOS as though the disk has fewer cylinders and more heads than it actually does. In other words, it takes advantage of the fact that hard disks have relatively few heads and lots of cylinders by shifting the balance between number of cylinders and number of heads so that both numbers lie below the above-mentioned limits (1024 cylinders, 256 heads).
With BIOS LBA, the hard disk size limitation is virtually removed (well, pushed up to 8 Gigabytes anyway). If you have an LBA BIOS, you can put FreeBSD or any OS anywhere you want and not hit the 1024 cylinder limit.
To use my 1.6 Gig Western Digital as an example again, its physical geometry is:

(3148 cyl, 16 heads, 63 sectors/track, 512 bytes/sector)

However, my BIOS LBA remaps this to:

(787 cyl, 64 heads, 63 sectors/track, 512 bytes/sector)

giving the same effective size disk, but with cylinder and head counts within the BIOS API's range (Incidentally, I have both Linux and FreeBSD existing on one of my hard disks above the 1024th physical cylinder, and both operating systems boot fine, thanks to BIOS LBA).