Get your antivirus program up to date and boot into Safe Mode. Note that some viruses can hide themselves from your antivirus program in normal mode, so you really need to scan in Safe Mode. To get into Safe Mode when you first power up, hit F8 about once a second until you get the menu and select Safe Mode. Then run a full system scan.
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Thought Avast was supposed to stop these before I got them. Any way to get rid of it without going to Best Buy geeks or someplace? Barb