Disconnect all peripheral devices from the computer - the speakers, the wireless PCI card, the printer, any other external device you have added, and physically disconnect the computer from its internet connection.
When you first boot the system look at the bottom of the screen to see if there are instructions to enter Compaq's recovery utility - there should be if it came with neither a Windows Disk or a Restore Disk from Compaq.
It is probably the F10 key, although that may vary.
From Compaq support:
Just after the first screen appears (the logo screen), press the F10 key repeatedly until a recovery menu appears.
Select one of the following procedures, depending on which recovery type you want to perform:
To perform a standard system recovery, click Next, and then click Yes.
(Try this first as it will not reformat the drive and you will keep your data and programs)
To perform a destructive recovery, click Advanced, (select Destructive Recovery) and then click Next.
CAUTION: A destructive recovery will format the hard drive. This will delete all the information on the hard drive and reinstall Windows XP and the original software that came with the computer.
Read and respond to each window and screen that appears.
After the System Recovery is complete, the PC restarts and continues into Windows setup. Complete the setup screens and wait until the computer finishes the setup.
NOTE: It may take a long time to complete Windows setup. This time varies and may take over several hours, depending on the amount of files that were stored in the user account folders (for example, My Documents and the Desktop).
After the recovery is complete reinstall all Windows Updates, your antivirus program and any program you installed since the computer was new.
Edited by Enthusiast, 01 August 2006 - 05:50 PM.