[Paint.net version 3.5.5]

Alright, as my psychic abilities are a bit low today, you're going to have to give us some more details...,

What OS are you using XP, Vista or Win7 (32 bit or 64 bit?)?

What service packs are installed?

Which incarnation of the .NET framework is installed?

How far does the installation get?

I guest why installing a sw should be so difficult ?

I'm using hp pc with W7 pro installed, previous version of Paint.net worked correctly now I cannot use it any way , 3 hours of trial with no success