It could be caused by several things but most likely WIndows Update.
The solution for failed updates is to System Restore to before the updates and reinstall singly. Most times that is enough.
If this is preinstalled Win7 from a factory OEM PC then you have an inferior install to begin with so I'd do what most tech enthusiasts do and
Clean Reinstall - Factory OEM Windows 7.
At the minimum I'd
Clean Up Factory Bloatware
Otherwise besides the steps given I'd go over your install using the
Troubleshooting Steps for Windows 7 which will find and fix most problems.