BleepingComputer.com: my window 7 has "this copy of window 7 is not genuine build 7600"

what do i do my window 7 has "this copy of window 7 is not genuine build 7600" and my system is slower than before.

i used HIJACKTHIS software to scan it, please who can analyse it for me. the log file reads:
Mod Edit: Removed malware log data, see No DDS, HijackThis, or ComboFix logs should be posted in this forum. - BleepingComputer.com - http://www.bleepingcomputer.com/forums/forum-56/announcement-45-no-dds-hijackthis-or-combofix-logs-should-be-posted-in-this-forum/ ~ Hamluis.

This post has been edited by hamluis: 15 January 2012 - 12:45 PM

You need to provide basic information about the system manufacturer and model...what your problems are...when they began...any onscreen error messages, etc...if you really want someone to be able to guess at what might be wrong with your system.

"This copy of Windows 7 is not genuine" messages...occur for any number of reasons, none of them have anything to do with malware.

Simply put...reactivate Win 7, either online or via telephone.

Louis

http://answers.microsoft.com/en-us/windows/forum/windows_7-windows_install/windows-7-build-7600-this-copy-of-windows-is-not/05ed572a-9795-4c62-9a68-d314e681e274