Windows 7: Installer Service won't work (including backup)

Hi. Hopefully you guys can help me out here.

I was using Revo Uninstaller to get rid of some unused applications, and I accidentally uninstalled "Steam". I went to reinstall it, and it told me the installer service didn't work. I just assumed it was one of those problems that would go away when I restarted my computer, so I did. The problem is still there, plus I'm getting errors with Asus Splendid Utility. Also, now my network icon is constantly showing disconnected, even though I'm connected to the wifi.

Newegg.com - Recertified: ASUS G60VX-RBBX05 NoteBook Intel Core 2 Duo P7450(2.13GHz) 16" 4GB Memory DDR2 800 320GB HDD 7200rpm DVD Super Multi NVIDIA GeForce GTX 260M

That's my computer.

Edit: Also, I went to make a backup dvd so I could restore to one of the restore points revo makes, and I got an error. It's a Windows Backup error. "The backup application could not start due to an internal error: Class not registered (0x80040145)."

Aaaaaand, my sound isn't working either. If I play a youtube video, there's no sound, and if I start a song in Songbird, it just doesn't start. Crap. I'm thinking I might just need to reformat, as much as I don't want to. Any opinions?

the same thing happened to me...jbut i admit i was doing some naughty stuff...have you done any downloading the past few days

Naughty?

At least try it in a virtual machine running Ubuntu.

For the OP run sfc/scannow at an elevated command prompt.

well right after i downloaded a patch off rapidshare, i uninstalled something and i restart, sys restore is disabled and the network symbol was no internet access but i could connect

i just reinstalled my os

A patch on rapidshare? Right. . .