Start up your computer into safe mode, go into your control panel and run the system restore, restore your computer to the earliest date shown.
Unplugging your computer whilst it is on is not advisable it will cause the check disc to run at bios.
The check disc can take up to an hour to complete depending on the size of your hard drive, if it completes fully and you still see the start up warnings, it is more than likely a driver or incompatible software, restoring the system returns the computer to an earlier date when your machine was working OK.
If you still have problems let me know and I will attempt to help further.
Cheers Shewy