Installation Incomplete Due To Missing File

I tried to install Bitdefender Free Version but it does not complete and hence become active. The reason I suspect is because of an error that pops up saying some file is missing .NET Framework: v4.0.30319. Have no clue what that is. Installation goes into an endless loop asking for that file.


Anyone here has any ideas? I am running XP3 and until now was using MS Security Essentials with no problems. Just wanted something more powerfull, but Bitdefender wont work.