Corrupt Windows 7 help needed

Hi
This is my first post, so please be gentle with me.
I Have a problematic installation after a virus which is now removed.

It refuses to shut down and hangs.
When boots there is a black screen with a mouse curser straight after the welcome page and can take 5 min`s to boot.

Can`t seem to add / remove some progs as they hang mid way through.
Hangs on Microsft updates also.

I`ve tried sfc /scannow as administrator and all I get is

Microsoft Windows [Version 6.1.7600]
Copyright (c) 2009 Microsoft Corporation. All rights reserved.
I:\Windows\system32>sfc /scannow
Windows Resource Protection could not start the repair service.
I:\Windows\system32>

I`ve googled this and the appropriate services are in manual as suggested.
Please help.

I don`t have any backups and the system restore dosnt work.

Try booting from the install dvd, then run an OFFLINE SFC scan. Heres a walkthrough.

How to Run the System File Checker (Sfc.exe) Offline in Windows 7 and Vista - The Winhelponline Blog

If that doesnt help, a repair install or a full clean install may be the only options.

I hope you have run a scan with some good tools like MBAM and hitman?

Hi.
Thankyou for your replies.
I booted to my Win 7DVD and tried off line scan.

Still get

Windows Resource Protection could not start the repair service



Eddie

You are likely still infected. Some infections require the HD to be wiped with zeroes and then clean reinstalled using your Recovery Disk set, or your Win7 installer.

See if you are able to install Avast5 to run its boot scan, which is required for serious infections since viruses have no place to hide (in running OS files) in boot mode.

If not I would try running a bootable CD scan from one of the free bootable AV downloads here: FREE Bootable AntiVirus Rescue CDs Download List

Let us know how this sorts out so we can advise you further on more drastic measures including running Factory Recovery, or wiping the HD to clean reinstall.

I have installed Avast and looked at the boot time scan.
That is only for 32 bit Windows unfortunatly.

I`m running a full scan anyway

Sorry man, I would burn the bootable AV scan CD linked before for Malwarebytes or your favorite and run a boot scan as well.

Also download Malwarebytes to the desktop to run it there, too.

But you likely won't get completely clean until you run a boot scan.

Then there is only one last place infection can hide and that is in memory. So install Spybot, update and run in Safe Mode as it can flush viruses from RAM after requesting a restart.

An infection presenting as yours is cannot always be expected to be cleaned up fully. You should start looking at options to either run Recovery Disks or Clean Reinstall using Win7 installer for your version. Do you have factory or retail Win7? What disks do you have?

Back up your data to quarantine where it can be scanned thoroughly using MSE, Malwarebytes and Spybot or SuperAntiSpyware.

Read over these tutorials to know what's involved:
SSD / HDD : Optimize for Windows Reinstallation
Clean Install Windows 7