If you want to increase the core and memory clocks past the defaults that "CoolBits" allows...First, move the clock sliders all the way to the right (under the "Clock Frequencies" tab in Display Properties) and click Apply. The Nvidia "CoolBits" utility allows for a 25% overclock over the default speeds (I'm assuming that you want to go past the 25% limit).
Next, you'll need to locate the "Simpsons" Registry keys (open the Registry editor by typing
regedit in the Run box | Edit | Find...and type
Bart in the "Find What" box (before doing a "Find", make sure all the Keys are collapsed...and highlight "My Computer"). It would also be a good idea to export at least the Key in which the "Simpsons" DWORD values reside, just in case something should go wrong.
The "Bart" setting basically stores the default gpu/mem clock speeds for your card.
The "Homer" setting stores the current info on your card.
The "Krusty" setting stores the new Memory and Core clock frequencies.
The "Marge" setting enables clock speed adjustments (Can be 0 or 1)
When you find the Simpsons Registry keys, just copy "Krusty" to Bart" (edit the "Bart" DWORD value to equal that of the "Krusty" DWORD" value)...you can now go past the 25% limit.
It should look something like this when you're done...
"Homer"=dword:000c7516
"Bart"=dword:7728a68b
"Marge"=dword:00000001
"Krusty"=dword:7728a68b
"Lisa"=dword:00000000