strange diskcleanup sp3 message

[adbp1]

was doing a regular disk clean-up today and this message came up


any ideas what it is and why it came up??
should i be worried?

 

[binaryknight]

its windows system file check.
basically windows has noticed that one or more of your system files has been replaced by a different or modified file.

have you used any programs or hacked uxtheme.dll to allow non standard themes?
patched usb polling rate?
patched tcpip limit to allow more half open connections?

you can disable the check its what i do