I have also read a magazine article (from same source) which says that the current drivers should be removed before installing the upgrade. This is not mentioned in the video.
Is it necessary to remove the current drivers?
I would always remove the drivers from the device manager in case it causes a conflict, sometimes the old drivers can reinstall themselves, it keeps the system clean
Visit the Nvidia website and check out that your system is compatible for your proposed card. I have a fairly basic system, running XP with a 32MB graphics card – and I can tell you that my motherboard can only just cope. Occasionally the display will blank when the PC is doing too many things – it would be a complete waste of time and money, me installing a better card; the same might be true for you.