Windows 7 - Seven RTM more unstable than RC

I've noticed that the RTM version at least in my case is more unstable than the RC.
I have a laptop HP compaq 6715b, I tested the RC on the laptop with no issues at all. everything looks perfect.
When the RTM came out to the MSDN portal I've downloaded (64 bits Ultimate) and installed on my Desktop (Pavillion m9350f) and did a new install on the laptop too.
On the desktop I had to go back to Vista because from time to time the CPU was at the top, when I checked the Task manager and click on the resource monitor the System Interrupts were consuming all the CPU, I understand that the System interrupts could be any component and is a little difficult to know which component could be. I Updated all the drivers on the system first using the windows Update and then using the latest version for the drivers, some of then were not available for & but I used the Vista one, and in appearance these doesn't have any problem.
But after a while again the same issue the CPU gets to the Top for the System Interrupts. I had to go back to Vista beacuas ethe system was unusable with 7.
------------------
That's one case on the other scenario the laptop worked perfectly with the RC but now with the RTM things are different. I did a fresh install to the RTM, and the system looks fine with no problems at all. But from time to time the system now gets hanged usually when I'm coming from sleep mode, on the RC I didn't had this issue.

I don't know maybe I have to wait for the first Service Pack to install again Seven on my desktop, or maybe some of you have the same system and don't have any problem.
These are my system Specs:
Desktop: HP Pavillion m9350f
Product Specifications*

For the Laptop:
Compaq 6715b
HP Compaq 6715b Notebook PC specifications - HP Small & Medium Business products

Thanks!