I got this computer new a couple of years ago when I went back to take some college classes. It is a HP ProBook 4525s laptop running Windows 7 Professional 32 bit that came installed, COA sticker and all. I have had some help here cleaning malware off of it but this popup that shows up about every hour saying that my windows is not valid is getting very tiresome. I am having money problems now so I think I will have to sell it to keep my desktop upgraded. I am just going to get a barebones kit and put my drives in but I can't sell this laptop like this. Shoot, it's getting aggravating just to use it and this model still sells for a little better than $300 used. Does anybody know what I can do to stop this thing? I thank you in advance for any help if you get the time. You guys have been great. Thanks if you get the time to help.