No problem. I use WinDoctor myself. Right-click on the section with the unrepairable program files, and click "problem details." It will say something like, "such-and-such was unable to access the necessary program blah-blah.dll"

Blah-blah.dll is the program you need to find. Do a Google search with the filename and extension (.dll) as it shows up. For example, if you search for msvcp80.dll, one of the results will be " - msvcp80.dll, free download." Click on that, and you can download the file for free. Save the zip file to your desktop, extract the contents, and copy the missing file to your WINDOWS\system folder.