When playing high definition video files the video lags PRETTY bad. I'm not all that computer literate so I'm not sure what factors determine this. I don't have anything too FANCY for a computer, just a 1.7ghz with 256mb RAM. The graphics card is pretty old, a Geforce 2 MX/MX 400. Anyway just wondering if there is a quick way like adding a bit of RAM to remedy this. Thanks in advance.What OPERATING system? How much RAM on the video card? What kind of processor exactly? What types of files specifically?

If you don't know, you can download and run Everest Home and make a report which will show all of this.

http://www.majorgeeks.com/download4181.htmlHD Video will lag on that PC.
More details would help, but I'd suggest at least 512Mb RAM, preferably more, and a NEW graphics card.
Depending on the CPU, possible a new CPU might help.
That's just basic advice, more details would lead to better advice.Okay thanks, although it looks like I won't be able to fix that cause my DVD burner is crapping out now Thanks anyway.Bah, DVD players/burners are easy enough to replace . IMHO your processor has enough oompa to get the job done so long as it's not tied up with lots of other programs running. I have a 1.5 Ghz proc and it plays HD video pretty good. I have 1.24 Gigs of RAM installed, which leads me to believe that your machine could use a bit more in that department. Your Graphics Card also needs a boost. I'd say http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=1776106&CatId=933 that ought to do, but you will need to see if your power supply and AGP slot are up to the job.

Maybe that's too much info, but better too much than too little .