Windows 7: Need to restore Windows, but some malware is blocking software launch

My sister's computer is an HP Pavilion dv5t-2200 notebook PC running its native OS, Windows 7 Home Premium x64. In the last 24 hours, Avast found and attempted to remove some sort of malware. After the reboot, it recommended a full scan. After the scan was completed, the computer rebooted again. This is where the real problems began.



With the exception of core programs and services, no other program will launch. Not Chrome, not AIM, not even Avast!. The only HP program still installed on the system, HP Support Assistant, will not start. Attempting to use Windows System Restore results in a BSOD as the computer is shutting down to begin the restore process. Upon returning to the desktop, a dialog box recommends that we run chkdsk, but of course that won't even launch.

Internet Explorer will launch, but the campus network requires a third-party client software install. Unfortunately, that's another program that will not launch.

The computer has a recovery partition, but HP Recovery Manager is not installed or cannot be found, and attempts to download and install it have failed because 1) we cannot access the Internet to download it to the hard drive, and 2) it could not be installed from a flash drive containing the softpaq from HP.

UAC is turned on. Maybe this is part of the issue?

I'm on the phone with HP Support right now, but I'd like some feedback from your end.

Pressing the f11 key during startup on a computer with an HP factory image will start the system recovery process even if the prompt is not displayed.
Recover Windows 7 Operating System Using HP Recovery - HP Customer Care (United States - English)
Performing an HP System Recovery in Windows 7 - HP Customer Care (United States - English)

How to make HP Recovery DVD disks:
Recover Windows Vista Operating System Using HP Recovery - HP Customer Care (United States - English)

How to make HP Recovery USB disk:
Creating a Recovery Disk on a USB Flash Disk HP Pavilion dv6700z CTO Entertainment Notebook PC - HP Customer Care (United States - English)

or
You can Order HP Recovery Disks from here:
Compaq Mini CQ10-500 PC series*-* HP Notebook PCs - Order Recovery Discs for Windows 7, Vista, or XP - c00810334 - HP Business Support Center

Hey there.

It is believed that the factory image was corrupted by this trojan. So we're ordering the recovery disks. Thanks anyway.