Cannot access windows management instrumentation software message.

This is the full message I am getting:
"Can't collect information, cannot access windows management
instrumentation software. Windows management files may be moved or
missing."

I seach the Internet, started WMI services, deleted repository folder,
but nothing helped.

Now I tried to do:
start/Run, type: sfc /scannow
but here is my problem:
this is a laptop without CDRom of floppy. I installed WinXp Prof (over
Win2000 prof) using network connection with my desktop and using CDRom
from the desktop.
Now when I issue sfc /scannow I am getting a message:
"The network location from which the files shoud be copied \\desktop\g
is not available...".

But the network IS AVAILABLE. Using Window Explorer I see the WinXP
CDRom!!!

I have anough disk space to copy CDRom to HD of my laptop, but I don't
see any option to point it to this location.
Any ideas how to solve this problem?

Thanks,

Zalek