I am trying to do a clean reinstall of Windows 7 professional edition, but I can't find the original disk or the recovery disk. However I do have the CD key. Is there a way I can get Microsoft to send me a CD/download an image of Windows 7 to reinstall from, or is there an image of the OS already saved on the system (I have a lenovo thinkpad w500 that came with Windows 7 professional edition).
There are .iso images of the DVD for the various version of Windows7 that can be downloaded from the web. But first you should check if there is still the recovery partition on the hard drive from which a restore to factory configuration could be performed. Performing such a restore will put the hard disk contents in the same condition as when you unpacked it. Your Thinkpad most likely did not come with any disk. There is a utility to burn the recovery disk(s) yourself. The last time I checked, Lenovo sold the recovery DVD for Win7 for about US$40.
If you do install from a standard Windows 7 DVD, then you will have to go to the Lenovo site to download and install all of the necessary drivers and apps that originally came with the Thinkpad.