2 pc's 2 problems

Hello, so I have 2 computers, one is a labtop and one is a desktop. labtop runs xp, destop vista.

The problem with the labtop is this: A little while ago a caugh a nasty virus that was making fake virus alerts pop up on my computer, I then got myself avast and ran the boot scan. After the boot scan I logged on and there were no icons and no task bar, only my wallpapper, I then went into safemode and did a system restore to just before I ran the avast, This fixed the no icons problems but i still had the fake alert pop ups. also when ever try to go on certain site like youtube a page comes up saying "the site is resticted" but i easly got around that with a proxy server. any way after the system restore i got my self malwarebytes and ran that, after the scan i restarted the labtop and logged on. the pop ups stop but my was unable to connect to my internet wirlessly or with a cable so i did the system restore agian but to same restore point a last time but when i logged on after that, once agian there were no icons and no task bar and when I hit [ctrl+alt+delete] it tell me it was disabled by the admin, but I am the admin.

Now the problem with the desktop is simpler: I removed a stick of ram to check what kind it was, but after i put it back in and turned on the destop back on it showed a black sceen saying " insert boot device"