With Nvidia it's pretty easy to edit to .inf/registry to get any refresh rate you want.
Easiest way is prior to installation:
-Extract driver to a directory
-Open up the .inf file in notepad
-find the string "nv_modes". There should be a line looking something like this:
HKR,, NV_Modes, %REG_MULTI_SZ%, "{*}S 640x480 1280x768 1280x800 1360x768 1680x1050 1920x1200=1;800x600 848x480 960x600 1024x768 1152x864 1280x960 1280x1024 1600x1200 1920x1440 2048x1536=3B;"
Now, what you can do here is set the resolution you want equal to any given refresh rate, in hexadecimal format, prefixed by 80. So suppose you want 1024x768 to run at 150hz. First step is to calculate what 150 is in hex. I do this by simply loading up windows calculator in scientific mode, type in the value I want and then his the Hex radio button. This tells me that 150hz is 96 in hex.
Now you just edit that line in the inf file to set 1024x768=8096. You can use semicolons to seperate the values from each other, like this:
HKR,, NV_Modes, %REG_MULTI_SZ%, "{*}S 640x480 1280x768 1280x800 1360x768 1680x1050 1920x1200=1;1024x768=8096;800x600 848x480 960x600 1152x864 1280x960 1280x1024 1600x1200 1920x1440 2048x1536=3B;"
As you can see, all I did was remove the existing entry for 1024x768 (grouped with a bunch of other resolutions), and stick it in the middle on it's own, set to a value of 8096 (80, plus the hex value for 150hz).
After saving your changes to the .inf file and installing the driver (using the setup.exe from that directory), 150hz should now be available for that resolution.
