Problem loading URL in QuickTime

Hi,
While I was using QuickTime at home, this error message I pasted below appeared on my screen, that said it needs a more higher version.

The QuickTime Plug-in requires the QuickTime
System extension version 5 or later.
QuickTime is available from Here
I came across this error, when I wanted to use QuickTime to go to any site. I am using QuickTime 7 and Windows Home Edition, with anti virus installed to my computer. I scanned my computer for some virus, but none was found. I restarted my computer and rebooted again. I tried again, and the same error came across my screen.
I don't know what to do with this error.
Please help me.
Thanks.
