It sure sounds like a problem inside your system.
If the VC runtime library itself has been corrupted, then they need to be reinstalled. And that's the problem. Because Windows itself is written in VC++ and uses those same runtime libraries, they get installed when you install WIndows. No other program's installer would actually install/update those core DLL's. Unless you know exactly what you are doing and are capable of selectively extracting those from the cabinet files AND using the preboot command box to copy them to the appropriate place, then a reinstall of Windows is the easiest way of getting the correct files again.
If it's DirectX that is corrupted, you could always try to run it's setup program again. But I don't know how intelligent that setup routine is. In other words, if it's capable of detecting and replacing corrupted files.
EDIT: Before you run off and do a format, you can try a hot install first. Basically, that means running the Windows setup program from the currently booted desktop, and using the same target directory as your current Windows installation. If you have the correct version of Windows (basically, a non-OEM version), then it will reinstall itself, while preserving your registry, desktop and start menu
Jan Peter