As much as I want to have fun with this thread, I will be good this time. More information such as, I just upgraded to Windows 7 or I spilled water on my keyboard, etc.. would be helpful to judge what your problem may be.
My guess is you have a keyboard and mouse that's not compatible with Windows 7. I had that same problem so my spidey senses are telling me that's your issue.
Give more detail and I may be able to give a better answer...