Hello deralickt and welcome to Seven Forums.
Are you receiving any error codes? Are you able to boot your machine in Safe Mode? If yes, see if you can access System Restore and go back to a date/time prior to the update. If you don't have a restore point you could also see if that update is showing in Windows Update History. If it is, try uninstalling it.
Safe Mode System Restore Windows Update - Uninstall an Update
The failed update may have damaged or corrupted some system files. From Safe Mode you could try running a System File Checker scan from an elevated command prompt (option two.) If problems are noted run the scan 3 times rebooting in between each scan.
SFC /SCANNOW Command - System File Checker
Since you have an install DVD you could also try a Repair Install to fix your currently installed Windows 7 and preserve your user accounts, data, programs, system
drivers, etc.
Repair Install
A repair install may require that you reinstall a bunch of Windows Updates. I found it's safer (but more time consuming) to install just a few at a time rather than all at once. If you install a few at a time you can reboot, see if there are any issues, and if there are, you'll know exactly which 3 or 5 or 10 updates you need to remove. Reinstall them one at a time. They'll either all install correctly or you'll know exactly which one(s) are problematic. (If you install all at once and later find out there's a problem it's almost impossible to know which update is involved.)