Touchpad and Keyboard not working (including external devices)

Hi,

I am using an rmbp with win7 and macosx.

Win7 on my bootcamp partition was working perfectly(4 months+) until now .I restarted my system and realized that the touchpad and keyboard are not working(inluding external mice/keyboard).I can boot into Macosx and the mouse and keyboard are working perfectly so its not a hardware problem.I havent set any restore points and have tried all the other recovery options (using f8 before booting) but to no avail

I have read some other solutions which involved opening the device manager but I cannot press anything when I login to windows.Does anybody have any idea except reinstalling windows? I would really appreciate any help !

Cheers