That is the Windows kernel and can be due to many things, which would take a lot of luck and effort to find. In the end a clean install is the best fix, although a repair installation can save a lot of time.
To do a repair install follow the guide here for REPAIR INSTALLATION. A repair installation will save your programs and files and just replace Windows, you just need to do the updates.
To save time on the updates, download the latest SP1 iso image of the same version that you are using from DIGITAL RIVER.