Reboot and tap the F8 key repeatedly. Look for Repair My Computer on menu, select it, see if it finds anything to repair. Next click through to
System Recovery Options to run Startup Repair repeatedly until it reports nothing to Repair.
In some cases onboard System files are corrupted requiring Startup Repair to be run from Repair CD, so make one now in Backup Center as you will need it if Win7 stops booting.
System Repair Disc - Create
Next run
SFC -SCANNOW Command to check for damaged System files to repair. You may need to run it repeatedly until files are fixed.
If this fails to solve problems, find a Win7 installation DVD for your version to run a
Repair Install
which is an upgrade over itself of the same version, keeping all files, settings and programs in place.
As a last resort, back up your files and run HP Factory Recovery from it's partition at boot, choosing the minimal version if available:
HP Backup and Recovery Manager.
Make your Recovery Disks as a backup in case factory recovery fails when run from it's partition at boot.
