I have a lovely PC. It's all fast and wonderful. It plays games such as F.E.A.R, Black and White 2 and The Movies perfectly well, and does every non-games-related task I wish to throw at it without breaking a sweat. Well, except for one thing.
Playing a video. AVI, mpeg, mov, whichever. Doesn't matter whether it's in Media Player, Quicktime or even iTunes, either. If I double-click on a video, it loads up the appropriate movie player and then the PC freezes completely before resetting. If I try streaming one over the internet, it gets to the point where it should start buffering before the exact same thing happens.
There are a couple of slight exceptions. It seems videos that are integrated into web pages via Flash (such as on the front page of Gamespot.com) are fine, as are full screen ones within games (Bink encoded? I forget the actual term). It's just any standard video causes a reset.
I'm currently running Windows XP Pro SP2 on an Athlon 2000+ with 512mb memory, around 100gb of free hard disc space and so forth. My video card is a BFG Nvidia Geforce 6600GT OC (AGP) with 128mb. The problem wasn't there until my brother rebuilt my PC due to a slightly clunky hard disc.. then the problem arose. It has since been reformatted and had Windows XP installed all over again over this weekend.. and yet, the problem remains on a nearly clean installation.
Any ideas? If you need any more details, let me know.
(Most recent nVidia drivers being used.. 81.94. But changing to older versions makes no difference..)
Could it be a power supply problem like this: Click Here (ask.metafilter.com)?
If I'm remembering correctly, a buddy of mine had to get a larger power supply when he bought a new video card, because his computer didn't work otherwise. Maybe your new HD (and other new stuff) is sucking more power than the old one, and the video card is wheezing?
When I built my computer, I used a website similar to this (jscustompcs.com) to decide my power supply. Not sure how accurate it is, but my computer hasn't exploded yet.
Basically, to the letter, I have exactly the same problem. I tried turning off the Direct X stuff (as suggested), and while it may be a bit ropey, everything DOES then play. It's confusing.
(I have also got in touch with the guy who started that thread via AIM.. uprating his power supply didn't fix it, and nor has anything else he's tried since. I guess it helps to know that I'm not alone here, though.. so thanks for the link. )
If you know what sort of processor you have, you should be able to go to a PC shop and say "I need a heatsink and fan for a (insert processor here)" Then its up to you to get the right priced option for you.