intel t7500 dual core processor performance/usage problem

[watcher0]

Hello, I've made a clean install of Windows 7 Ultimate a few days ago, and I started to encounter the following problem after 30-60 minutes:

It usually happens when I'm running a computer game (any game), I experience a sudden fps drop, even though before that, on maximum quality the game was running perfectly, becomes unenjoyable, quit the game. The CPU meter gadget shows 100%, and even after I close everything, browser, windows explorer, the best I get at idle is 70-80%, and if I try to open anything at all, it becomes stuck at 100% again. So I open task manager and go processes, put them in a descending order of processor usage, and see that they nowhere near add up to 100%, even though at the bottom the task manager says CPU usage is at 100%. Phyiscal memory is usually around 20-60%, no problems with that.
If I go to Performance tab, and click on resource monitor, I experience the same thing: the actual usage is nowhere near 100%, I can't see any processes that would explain for the performance drop, in fact the highest demanding process is the resource monitor itself.

The problem presists until I restart the computer, shutting down takes much longer now.
I've been trying to find a solution online for two whole days now, it's very frustrating.

It's a HP Compaq 8510w laptop with Windows 7 Ultimate x64 Build 7600
Intel Core 2 Duo T7500 (2.2 GHZ)
Hewlett-Packard 30C5 (Intel PM965 (Cresline-PM) + ICH8M-E)
4GB memory
nVidia Quadro FX 570M [HP]
Intel 82801HB ICH8 - High Definition Audio [B1]
I've tried several suggestions:
Disabling HDAC in Device Manager (High Definition Audio Controller)
Disabling Audio Enhancements in Sound>Speaker Properties
Installing the very newest drivers, including chipset drivers
Running programs in XP compatibility mode
Disabling the gadgets

I've no reason to think I've been infected by malicious software, I can't find any suspicious processes running.

Anything else I could try? This is driving me absolutely mad.

 

[badger906]

first of welcome to the forum.

I suspect a rogue program, but as youve updated drivers youve already covered what you can do. it could be a known compatibility issue with your hardware and a specific driver, but i cannot comment for sure as theres alot of hardware combinations.

however, heres the bad news, i recently had a laptop to repair that had the exact same problem, and i couldnt fix it for the life of me, no matter what i tried, the problem even occurred in safe mode (try this if you haven't already) and i eventually after much shouting and swearing, put the problem down to a dying CPU.

 

[watcher0]

I've found the cause of the issue, it's not down to a wild process or overheating, but for some other weird reason, the processor is forcing itself to underclock to 195 mhz at x1 from the normal 2200 x11. I've edited all available power settings in Windows 7 to have the CPU always be available 100%, I also downloaded RightMark CPU Clock Utility, forcing the CPU to be at 2200 mhz x11.
It worked for a little while, I was problemless for an hour, but then it came back... for some reason it still underclocks.
Suggestions?

 

[watcher0]

This is the readout after the problem occured and I alttabbed