Did you check in the Device Manager and make sure you Graphics card is still listed. You might need to download the original driver.
If that checks ok then you can scan for Malware. There is malware that will do this. It is not common.
Trojan Removal Procedure.
Removing infections from your computer is never as easy as aquiring them. Malware infections are not meant to be removed, so, it takes TIME and PATIENCE to get rid of them. ONLY RESORT TO A REFORMAT AFTER ALL ELSE FAILS TO REMOVE THE INFECTION.
This procedure works for all Malware. Replace the Ewido and AdAware SE programs with any AntiVirus or AntiSpy program you choose.
Download and Update Ewido (now called the AVG Antispyware). Do not run:
http://www.ewido.net/en/download/...
Download AdAware SE and update. Do the setup. Do not run:
http://www.filehippo.com/download_ad-aware/
AdAware SE Setup:
1. Select "use custom scanning options" then select "customize". Make sure the following options are enabled: "scan within archives," "scan active processes," "scan registry," "deep scan registry," "scan my IE favorites for banned URLs," "scan my Hosts file."
2. Select the "tweak" option. Under "scanning engine," make sure "unload recognized processes and modules during scan" is enabled. Enable "scan registry for all users instead of current users."
3. Under "cleaning engine" turn on "always try to unload modules…," "during removal unload explorer and IE if necessary," "let windows remove files in use at next restart," and "delete quarantined items after restoring."
4. Use the "select drives and folders to scan" option to ensure that your entire hard drive is scanned (if you have more than one hard drive, scan all of them (of course, do not include floppy and CD/DVD).
TEMPORARILY SHOW HIDDEN FILES AND FOLDERS.
1. Click Start, and then click Control Panel.
2. Click Appearance and Themes, and then click Folder Options.
3. On the View tab, under Hidden files and folders, click "Show hidden files and folders", and clear(uncheck) the "Hide protected operating system files" check box.
IMPORTANT: Files are hidden by Windows for a very good reason. It is not wise to experiment with these files. Unfortunately, to successfully remove modern spyware we must turn this protection off temporarily. Please turn the protection back on when you have finished cleaning your system.
EMPTY INTERNET EXPLORER BROWSER CACHE:
1. On the Internet Explorer Tools menu, click Internet Options.
2. On the General tab, in the Temporary Internet Files section, click the Delete Files button. Select the Delete all offline content check box in the confirmation dialogue box that appears, click OK. Click OK again.
RESTART IN SAFE MODE:
To do this you need to hold down or repeatedly tap the F8 key while the computer is booting (when the computer is displaying a black screen with white text). When the boot menu appears, use your keyboard arrows to select "Safe Mode."
Safe Mode can look quite ugly. The color may look bad, and all of your desktop icons will be very large. This is normal.
START THE SCAN WITH ADAWARE SE. THEN DO IT WITH EWIDO.
NOTE: Let AdAware complete its scan. Sometimes AdAware will be unable to remove everything that it finds and will prompt to be allowed to try again after restarting. If that happens, when the scan finishes restart immediately and allow the scan to finish.
When the scan and removal are completed REBOOT COMPUTER. This will restart you in normal mode. DON'T FORGET TO RESET HIDDEN FILES AND FOLDERS.
NEW RESTORE POINT:
The RESTORE POINTS may be infected with the Malware and cannot be used.
HERE'S HOW:
1. Click Start, and then click Control Panel.
2. Click Performance and Maintenance, click System, and then click on the System Restore tab.
3. Select the Turn Off System Restore check box, click Apply, then restart your computer.
4. Return to the System Restore Tab and turn System Restore back on.
TO SET A NEW RESTORE POINT:
1. Click the Start button.
2. Point to Programs, then navigate to Accessories, then System Tools, then click System Restore.
3. Choose Create a restore point, and then click Next.
4. In the Restore point description box, type a name for your restore point, and then click Next.
5. Click OK.
NOTE: If you are using Windows XP Service Pack 2 (SP2) and are unable to access the Internet after removing Malware, there is a command that may fix the problem. It works by resetting the winsock catalogue. Click on Start, then Run and type CMD in the box. Click OK. Type "netsh winsock reset" (no quotes)into the DOS window that appears.
ADDITION INFORMATION ABOUT TROJANS:
There are Trojans that fall into the Smitfraud family. These require the use of a specialized program for removal. Here are two sites that specialize in removing these:
http://www.internetinspiration.co.uk/rog...
http://siri.urz.free.fr/fix/smitfraudfix...