Where should i start.

Ok. My system specification is as follows: -



Intel QX6700 Quad Core CPU (2.66GHz)
Asus P5N32E-SLi Motherboard
2 x 1GB PC6400 800 MHz Ram
1 x GTX8800 graphics card
Windows Vista Home Premium 64 Bit edition o/s (OEM Version)

Now, when I first installed Vista I activated it straight away no problems
with all programs working correctly. However, I noticed that when I ran the
Vista test my CPU was running at 1 GHz so I restarted my machine & entered
the BIOS & defaulted it. I also turned off the speed step feature to allow
the CPU to run at it's set speed of 2.6GHz. (For anyone who is unsure about
what the speed step feature is it slows down the cpu when it's not under any
stress.)

Now I rebooted Vista only to find out that I could not access the vista
control panel or welcome centre since I turned off the speedstep feature but
also windows was telling me to activate vista again because it detected a
hardware change. So I clicked on activate & it says that the activivation
code is already in use. Therefore, I tried contacting Microsoft tech support
via email of which it was asking me to enter the product key of which I did &
it's states that it's invalid.

Can anyone help especially with regards to me not being able to access
certain programs when my CPU is running @ stock speed?