I have a now a Geforce GTS 250 card that does not seem to work properly. If I play a game or watch online videos, it will "flicker" and alert saying the driver has failed but recovered. I've tried installing the latest drivers from the manufacturers website, but that hasn't solved the issue. Could it be a power supply problem?
That's... not a problem with the card OR the power supply.
Just look at the issue: the DRIVERS have failed. Badly coded drivers.
Why download from the manufacturer's website? One should always get drivers from the designers' website, not aftermarket drivers. For you that means nvidia drivers, not (taking a guess) Zotac's out-of-date cruddy drivers.
I didn't mean to confuse. The driver I last downloaded was from Invidia.com. I just looked up my card, and used the most recent driver. I've done this several times, and before the last, I deleted any old driver files in the comp. The most recent driver now I believe is 306.97