re-installation

How far a frequent re-installation of Windows has affected the Hardware or the PC? Is there any suggestions?

Hi guyz, i live in hostel in 2-seater room, where my roomie sometime use my PC in my absence,there are some personal pics on my PC, which i've saved in hidden folder. I want to lock these files so he cant view in my absence. Before this i've used some "folder lock" & "fake folder" But sometime...

I use Webshots as my wallpaper changer. For last few days I am getting this error whenever I want to change wallpaper. Re-installation did not help. What to do ??