Windows 7 has High CPU Usage and slow performance

Mine is a clean install. I have pandora one, firefox, and MS Antivirus running (plus taskman and Resource monitor).  And no, before anyone asks, MS AV is not running a scan.

My CPU goes between 40 and 80 percent.

I'm running Win7 Pro 64bit. Dual Core Intel CPU w/8GB of RAM.  Dell E6500.  Nvidia

It doesn't do it all the time, but when it does, it just goes to ____ in a hand basket.

I've monitored various aspects of the system trying to catch the culprit.

From everything I can tell, it's a driver issue of some type.  Driver latency climbed through the roof (DBC Latency Checker).  My normal Latency is 500 or lower. When this happens, my latency is all over the place, spiking up over 4000.  DPC Latency Checker @ www.thesycon.de

Anyway, it magically resolves itself. I've tried stopping services and just about everything else I can think of.

It's so random. I've got the latest drivers, etc.

As I write this my CPU has been fluctuating been 30 and 50%. Incredibly high considering what I have open right now.

I have noticed that Windows Media Network Sharing Service (WMNSS) is running between 30 - 48% of my CPU all by itself. Last night I had absolutely nothing running and wanted to watch a DVD on my computer. I had watched one already but when I stuck the next one in, the CPU jammed itself at 100% and the computer became unresponsive. I tried to shut down processes that were unnecessary, but all this did was make the situation worse. The last thing I did was try to stop services on the WMNSS then the computer pretty much froze. I would have to force a logoff and each time I started the task manager or even clicked the START button, it would just freeze again.

I finally resolved this issue by restart--> going to msconfig-->shutting down a bunch of useless start-up items-->and making the start-up of WMNSS manual along with a couple other services.

Now my CPU is at 8 - 10% on the low end but the performance monitor is still showing heavy spikes in CPU usage every second. At least it is only a quarter of what I was getting, but it still is indicative of some kind of stability issue in the system. DPC Latency Checker is showing 200 µs upwards of 321 µs upon start-up of this (DPC) program. Looking at processes in order of CPU usage, I noticed how 4 - 5 processes are jumping all over the place in %. AVG firewall services are going from 0% up to 46% back down to 2% and so forth each tick. This is not the only process doing this. And no its not a firewall incompatibility issue. It is the only firewall/AV I have running.

Running an intel dual core processor with 6GB RAM on a 64-bit brand new computer, I should not be having an issue.

I'm hoping someone may have a permanent fix for this that creates a more stable environment.

Running into the similar issues as everyone else.

Computer starts fine, runs well for a short period of time (between 10 minutes to one hour) then the computer spike up to between 75% and 100% usage and will stay in that range until I restart the computer.

This problem originally surfaced after I had done an upgrade from Vista (64 bit) to Windows 7 (64 bit), but I've now done two custom reinstalls and on the second one I was still having the problems even though I hadn't touched my backed up files or installed any programs.

I'm using an HP system with an AMD Phenom Quad Core processor, 6 GB of RAM, an nVidia GeFored 9100 video card, and a dual monitor setup (*one DVI, one VGA).

Solutions I've attempted: UniBlue Registry Booster & DriverScanner, Shutting off all startup programs, Using Microsoft Security Essentials to scan for viruses.

No permanent fix.

I'm really close to just reinstalling Vista and demanding a refund from Microsoft that's how frustrating this is.

I've been scouring the web for an answer and still nothing.