Free antivirus software

A great free antivirus program is Avira AntiVir. It ranks among the best scanners in independant tests. Below you can find a download link for this excellent scanner and also a few tweaks.

Download:

Avira AntiVir

Tweak #1: Prevent display of ad for pro version

The free version of Avira AntiVir displays an ad for the Premium version everytime it updates its virus definition file. Fortunately, this annoying ad can be blocked. Follow the instructions below.

Windows XP Pro:

1. Start –> Run –> Type "secpol.msc" and press enter.
2. Click on Software Restriction Policy, then on Additional Rules.
3. In the menu, click on Action, then on New Path Rule.
4. Press the browse button and select the file avnotify.exe that is located in the installation folder of Avira. For example:
   C:\Program Files\Avira\AntiVir Desktop\avnotify.exe
5. Set Security level to Disallowed (default) and press OK.

Windows XP Home, Windows Vista, Windows 7:

1. Open Windows Explorer and navigate to the installation folder of Avira, for example: C:\Program Files\Avira\AntiVir Desktop
2. Right-click on the file avnotify.exe and select Properties.
3. Go to the Security tab and press the Advanced button.
4. On the Permissions tab, click on the Edit button.
5. Press the Add button.
6. In the object name field, type your Windows user name and press enter.
7. Enable the Deny checkbox for Traverse folder / execute file.
8. Optionally repeat the above two steps for the "Administrators" and "users" user groups.
9. Press OK a few times to exit all open windows.

Tweak #2: Silent updates

At default settings AntiVir will show a small update windows whenever it updates. Follow the following steps to hide that.

1. Launch AntiVir and click the Scheduler tab.
2. Right-click on Daily Update and choose Edit job.
3. Click Next until you reach the Display Mode screen.
4. Choose Invisible from the drop-down list.

Tweak #3: Disable splash screen after boot

1. Run the Registry Editor:
   Start -> Run -> regedit.exe
2. Navigate to the key:
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
3. Right-click on the value avgnt and select Modify.
4. Add /ns at the end of the command.