You don't need to be logged into an administrator account to run SFC on a Windows XP machine. You do, however, need to follow the advice of our Helproom Expert.
QUESTION My XP PC doesn't recognise the command sfc/scannow. I figured that this was because I wasn't logged into an administrator account and tried to switch from my standard user account using the command line; it wouldn't let me enter the password. Hitting buttons on the keyboard does nothing. Any suggestions, please? peaches10001
HELPROOM ANSWER An occasional bug can occur in XP that prevents you from typing in your password at the Welcome screen. Microsoft recommends using the Classic login screen to sign in. You say that your keyboard isn't working at this point, but this still might be worth a try: simultaneously press Ctrl, Alt, Del twice at the login prompt.
This should bring up the Classic login window, where you'll need to type in your username and the password. You can read more details about this workaround on the Windows support site.
However, you don't need to be logged into an administrator account to run SFC on a Windows XP machine. We suspect that the command prompt simply can't find the file. Direct it to SFC.exe by first typing cd C:\windows\system32 and then entering your request (substitute C: for the drive on which Windows is installed if necessary).
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