I've got a Lenovo n100 laptop that's 3 years old. It dual boots the original Windows XP that came with it and Ubuntu, and I just now noticed that the XP installation, on the Task Manager, only shows 1 CPU.
The device manager does show 2 processors (it's a core duo T2300), but it looks like one of them isn't being used. Googling showed that SP2 needed a specific hot fix to enable this, but nothing shows up on SP3, and when I downloaded the said hot fix it refuses to install, saying I have a newer solution.
(Just to make things clear, I checked and it's not that Task Manager shows all CPUs in the same graph.)
Does anyone know how to fix this?
Best Answer
Run the msconfig utility, go to the BOOT.INI tab, then click Advanced.
The NUMPROC checkbox should be unchecked to use all processors.
As a test, try to check it and see what does the drop-down list contain.
If it contains only the value 1, then something is really wrong.
NOTE : This answer is from 2009, please treat it with respect for its old age.
Especially : No downvotes, please.