I don't have a USB Stick and my CD Drive stopped working. I'm trying to do a clean install of Win7 on my Laptop which is currently running Win7.
Buy a USB flash and create a bootable Win7 assuming your computer can boot from usb, & I guess it can.
http://arstechnica.com/business/2009/12/the-usb-flash-drive/
Replace/repair the drive so it can read the Win7 DVD