Acer Aspire 5610 problem using only 1 core (50%)

Hi

I'm currently using Acer Aspire 5610 (bought 2 yrs ago) with windows 7
I got all the drivers installed (since everything was working fine till now)

But now when I tried to play some IWD II with my friends, but I've encountered a small problem with the CPU usage....
the problem is:



IWD uses only 1 core... and it's running with full power while the 2nd one is IDLE (the 2 small bumps are 2 earlier screen shots and the 2 bigger bumps are SVCHOST suddently out of nowhere taking full power of the 2nd core but it's not the issue here)

The problem is that the game lags.... As if my laptop was too slow for it.
I try to give IWD.exe a higher priority but didn't worked ( the hamachi was unable to connect after I changed it ) and the game was still lagging.

I remember I encountered such issue before (a year ago maybe) when 1 of the CPU cores was idle while the other was working at full capacity. I solved the problem back then somehow but I can't remember how (I think it was the driver issue)

But right now I have no idea how to fix it.... any suggestions ?

* Or Maybe it's the problem with the game/exe itself since I just tried to run other games and both CPU cores worked well (were used to support the games performance)

with regards

 

bumpty bumpty bump