Software still installed and intact yet not usable in any way, why?

Lets start from the top:

I was using my computer as I normally would have. Same thing, different day.

My windows got corrupted and was unable to boot. I inserted my windows XP SP2 disk and attempted to repair the windows installation yet the disk recognized the drive as practially annihilated so i'd need to reformat.

Defiance is my middle name.

I decided to delete the windows folder manually (long story made short) then continue with a fresh installation.

I've done so but now when I boot up, I still have all my files, games, programs, and everything intact YET things like my drivers, and installed programs set to run on startup do not appear.

For instance: I have Office XP, but my computer acts as if I don't have it on my computer. I have zonealarm firewall, yet that does not start up.

I figured that it was the USER that was the problem, yet there's no way to log onto it via the "switch user" option.

Help?

Software still installed and intact yet not usable in any way, why?symatec

You need to reinstall those programs. When then installed originally they dropped some library or other files in the windows system folder(s) and you've overwritten those. You could have lost registry entries too or other required files. You may get lucky by finding an install executable in the existing remaining directory but doubtful.

It's also possible for some programs that if you get into directory and recreate the shortcut to the executable file you'll be allright, but that's only the simpler programs. Best if you reinstall from original media.

Software still installed and intact yet not usable in any way, why?vista

no way to fix or recover it, i always reformat my computer and i learned that it is best to save the installer files of the softwares in a disc.
dont worry !try again !!it will be ok