The correct command is sfc /scannow.
Are you sure you don't have malware lurking around, lot's of that these days.
If you are unfamiliar with spyware/Malware, check out the articles at:
http://www.pcmag.com/article2/0,4149,1522416,00.asp
http://www.pcmag.com/article2/0,4149,1523357,00.asp
If you have XP or Millenium, it has a System Restore:
You need to disable systen restore before removals tools will work.
Turn off System Restore:
Click Start > right-click My Computer, and then click Properties.
Click the System Restore tab.
Select the "Turn off System Restore" check box and then click OK.
Click Yes when you receive the prompt to the turn off System Restore.
When you reboot, the system restore wont replace the automatically backed up file and reinfect you.
For the Spyware/Malware the two best Free scanners are AdAware 6 at:
http://www.lavasoftusa.com/
And Spybot Search & Destroy version 1.3 at:
http://www.safer-networking.org/index.php?page=download
After Installing each check for updates before proceeding. Both have several cool tricks, Adaware has a custom search that can search your Hosts file and your archived files as well. SPpybot S&D has an new program called Teatime that doesn't install by default you have to check the box ehn you are installing. SPybot S&D also has an Immunization program.
Another excellent program is SpySweeper from www.webroot.com, it allows for one update and then you need to purchase to get anymore updates. It will find a lot that the two free one didn't.
I also use PestPatrol which also costs money. It is located at:
http://www.pestpatrol.com/ and they have a free pest scan if you can stay on the Internet long enough.
Steve Gibson also has several really good security tools as well as his famopus "Shields UP" tester at:
www.grc.com
