it's not asking you to reinstall the game it's asking you to reinstall the latest direct x redist.
I guess I can just let the official microsoft site handle the rest of this How to download and install DirectX
alternatively you can try a secure file scan to see if it can see any damage to windows files. SFC /SCANNOW Command - System File Checker
One of the two should set you straight.
ps. also if you have the install disks for said games they sometimes have the most recent direct x redistributable installer on them.