A very good free anti virus. It is, in my opinion, better than Avira Antivir.
Ironically, it is from Microsoft. And there is a security built-in to check validity of genuine Windows system before installation.
There is a way to by pass it (ps: if after successful installation, the program itself calls for another validation, run the registry below again and the validation should pass. However, when it keeps requiring this on every reboot, I DENY 'System' full control in the registry on ...localmachine/software/microsoft/windows NT/current version & /wpa..., but 'System' can read. The outcome is slower login, but it works.):
Basically, install the antivirus program in offline mode, after installing this registry (create in notepad and save file with extension *.reg):
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\WPAEvents]
"OOBETimer"=hex:ff,d5,71,d6,8b,6a,8d,6f,d5,33,93,f d
"LastWPAEventLogged"=hex:d5,07,05,00,06,00,07,00,0 f,00,38,00,24,00,fd,02
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion]
"CurrentBuild"="1.511.1 () (Obsolete data - do not use)"
"InstallDate"=dword:427cdd95
"ProductId"="69831-640-1780577-45389"
"DigitalProductId"=hex:a4,00,00,00,03,00,00,00,36, 39,38,33,31,2d,36,34,30,2d,\
31,37,38,30,35,37,37,2d,34,35,33,38,39,00,5a,00,00 ,00,41,32,32,2d,30,30,30,\
30,31,00,00,00,00,00,00,00,00,0d,04,89,b2,15,1b,c4 ,ee,62,4f,e6,64,6f,01,00,\
00,00,00,00,27,ed,85,43,a2,20,01,00,00,00,00,00,00 ,00,00,00,00,00,00,00,00,\
00,00,00,00,00,00,00,00,00,00,00,31,34,35,30,34,00 ,00,00,00,00,00,00,ce,0e,\
00,00,12,42,15,a0,00,08,00,00,87,01,00,00,00,00,00 ,00,00,00,00,00,00,00,00,\
00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00 ,94,a2,b3,ac
"LicenseInfo"=hex:9e,bf,09,d0,3a,76,a5,27,bb,f2,da ,88,58,ce,58,e9,05,6b,0b,82,\
c3,74,ab,42,0d,fb,ee,c3,ea,57,d0,9d,67,a5,3d,6e,42 ,0d,60,c0,1a,70,24,46,16,\
0a,0a,ce,0d,b8,27,4a,46,53,f3,17
There is a simpler solution, thanks to sgsolve:
This annoying message can be removed by following the steps below.
only works on Windows XP.
1. Press WIN+R, type %WINDIR%\system32\drivers\etc and click OK.
2. Open hosts file with a text editor, add the following entries to the file and save it.
127.0.1.1 spynettest.microsoft.com
127.0.1.1 spynet2.microsoft.com
127.0.1.1 mpa.one.microsoft.com
Press WIN+R, type "%ALLUSERSPROFILE%\Application Data\Windows\Genuine Advantage\Data"(with quotes) and click OK. Delete the data.dat file in the data folder.