Windows Vista [Slow boot and freezing problems, etc after failed Windows Updates]

A little over a month ago, I installed a few windows updates (security definitions and updates, vista updates, Office updates) and my computer hasn't worked properly since. I just looked at the updates that were installed, and it says that they all failed. Since these updates, I've had a bunch of small problems all seeming to be with windows.

-Windows takes minutes to boot up (took under a minute before).
-When Windows does finally load, it freezes as soon as I click a program icon (ex. firefox). I then have to wait another few minutes until windows explorer is operating again. it used to shut down all together and restart, but now it just freezes.
-Often when Windows has booted up, an error pops us saying "Program: has stopped working" (there is nothing where the name of the program should be)
-Internet drops out after computer is on for a while (can happen after 15 minutes, or a few hours). I have full bars on network connection, but the connection doesn't seem to reach the programs that use the internet. Outlook fails when I try to check my mail and both IE and Firefox refuse to load pages, saying 'done' in the bottom left.
-some web pages freeze up my internet browser and take minutes to resolve. Myspace is the main offender here, whenever I open it, everything just stops.

I have tried the disc check utility, reinstalled some programs that use internet, and fixed errors in the registry. Still nothing seems to be fixed. I'm not sure where to go next, as there isn't just one main problem, but a series of smaller ones. Talking to some others, it seems like files are missing or damaged from windows, and reinstalling Windows would be my best bet.

 

The URL listed below might help to fix the Vista Install with out reinstalling Vista.

http://windows.microsoft.com/en-us/windows-vista/What-to-do-if-Windows-wont-start-correctly

 

Thanks for the link!

I tried to do a system restore immediately after these problems started happening, but even though I've always had it enabled and create frequent restore points, all of them disappeared when the problems started happening.

I have run the memory and hard disk checks, both came back with no problems found. My devices and drivers seem to be functioning as normal, and there are no software problems either. I have reinstalled firefox, and done a safe boot, but those don't seem to help either.

 

My computer is now free of malware, but the problems are still occurring (except for the internet dropping out). My next best guess is to re-install Windows, but if I do that I am going to reformat and upgrade to Windows 7.