Windows 7 - Can't update Avast or Windows Update... Desperately need help ASAP

For a couple days now, I havent been able to update Avast or Windows Update. I tried reinstalling Avast but it did not help. I have tried everything. I scanned my PC with every major malware program but they don't detect anything. What should I do?

I'm too scared to reinstall Windows 7. However, I will if I need too. I also want to format my disk in the process. How could I do this?

Also, I am scared that I wont be able to find the drivers I need for my GPU and such if I reinstall and format my disk. Where can I find these drivers?

Sorry about the messy text, this was sent from my ipod touch.

If you do reinstall, use this a guide: SSD / HDD : Optimize for Windows Reinstallation

Drivers can be found almost anywhere provided you know the name of the hardware you're using. The best idea is to go to the manufacturers website, as they will have the most up to date drivers.

If you want to do a middle-ground between a clean install and not reinstalling, you can do a repair install: Repair Install

But, chances are someone knows how to fix this so what a little while longer before doing anything drastic.

Uninstall Avast and install comparable free MS Security Essentials to see if it will Update.

Did you run the Avast Boot Scan which is the deepest AV scan you can get? Try also one of these bootable CD scans: FREE Bootable AntiVirus Rescue CDs Download List

Next run sfc /scannow to check System File integrity.

Check your Event Viewer>Admin view for repeat errrors.

Consider a Repair Install if problems persist and there are no further clues.

Is this factory installed Windows 7, or an in-place UPgrade from Vista? A clean reinstall might help you overcome corruption from one of these. Clean Install Windows 7

Use the drivers given by the Windows 7 installer and quickly updated via optional Windows Updates. Only change drivers if performance dictates or any are missing.

The biggest problem I see is that you haven't told us what happens when you TRY to update. We need to know what errors you are getting, what you are seeing on screen, etc.

I scanned my PC with every major malware program but they don't detect anything. What should I do? What programs did you use and could you update those programs?

AssaultRifle,
Did you folllow GregRocker's advice? Yes or No.

Yes, I tried everything, and nothing seems to work. Avast and Windows Update just cant connect to the server. I have tried many different WLAN connections and this still happens.

Clear your DNS cache and restore MS's original hosts file (sounds like you can't connect because malware has stopped it from doing so)

Copy and paste these lines in Note pad.
@Echo on
pushd\windows\system32\drivers\etc
attrib -h -s -r hosts
echo 127.0.0.1 localhost>HOSTS
attrib +r +h +s hosts
popd
ipconfig /release
ipconfig /renew
ipconfig /flushdns
netsh winsock reset all
netsh int ip reset all
shutdown -r -t 1
del %0

Save as flush.bat to your desktop. Right click on the .bat file and choose to run as Administrator. Your computer will reboot itself.

Now, run an online scan using Eset Free ESET Online Antivirus Scanner

Alright, will try this right now. I scanned with the last antivirus I could find on the internet, and it detected a bunch of "rootkit" viruses. No other anti virus has shown even 1 infection. I'll delete these then i'll try what you told me

ugh! not good