If it worked before a reinstall and not after, it may be a driver issue. Have you checked to see if you have the same driver you had before?
In games like WoW or anything I don't have an option to change the refresh rate. The options just have it locked at 60. I used to be able to change it to 100/120 before I reformatted my computer. I have tried turning v-sync on/off, restarting, getting the newest drivers and nothing has worked so far. The thing is I can get 100/120 hertz on my desktop it's just only in games that it's locked at 60. Thanks for any help or if you need anymore information just let me know. This is really irritating since I had it working before with no problems.