In that case can you click start then control Panel and then can you select the Add/Remove Hardware option then locate Apple Mobile Device Support and right click it then choose remove.
Once it is removed can you then open your My documents folder then open Music and open the iTunes folder.
From there can you right click on the iTunes music folder and choose copy then close the window and right click on an empty part of your desktop and choose Paste so that we have a copy of your iTunes library on the desktop.
Once that is done can you click Start then control panel and open Programs, Find iTunes in the list and give it a single click to highlight it then choose remove.
Once it is removed can you restart your computer then follow this link http://apple.com/itunes/download to download a fresh copy of iTunes to your desktop.
Once the program is downloaded can you install iTunes just like normal.
After it is finished can you then open iTunes and let me know if it will run properly and that all your music is listed.
If it is will you then connect your iPad and then follow the prompts and let me know if it will now install and then restore properly or if you get any errors.