According to the specs for your M50, it uses an integrated video adapter with an AGP slot for an upgraded video card. Judging by the rest of the computer's specs (Pentium 4 class hardware), it is a bit old for Windows 7. The integrated video adapter (part of the Intel 865G chipset) does not have a Windows 7 driver available, and depending on if you have an AGP card installed, you may or may not be able to find drivers for it. Windows Vista drivers should work, if you can find them for your hardware.
If the link you provided is for a card similar to what is installed in your computer, you should be able to go to www.nvidia.com and find a driver there.