Is it advisable to uninstall then reinstall DirectX?

[El Moose Monstero]

My laptop seems to have problems with DirectX - not major ones, basically, whenever I install a game, it tells me that I don't have the newest directx when I do. It starts to install the version from the computer, then basically stops instantly and tells me that it's finished installing it. I think it starts to install it then realises that it's already on there.

I'm wondering if this might be why a lot of my games don't work too well - Homeworld 2 crashes before it even starts, Empire at War plays the actual game component but doesn't play videos at anything less than about 1 frame per second.

I was wondering if it was possible or advisable to completely uninstall directx and then reinstall it from online. Reinstalling over the top of my version just seems to install a couple of additional components. It doesn't appear on add/remove programs, and online it suggested that it might cause problems. Is it worth doing? If so, how do I do it and is it likely to be the source of the problems?

[Vendetta]

It's possible, with a third party DirectX nuker, but I'm doubtful as to whether it will actually do any good. The DirectX installer checks your current file versions and installs the ones you need.

If you think one might be corrupt, you could try the system file checker. (sfc /scannow)

[El Moose Monstero]

I ran that, didn't seem to show anything. It only seems to effect game movies - in addition to the above problems, movies for the intros of X2 and HL2 both also run at very low and jittery rates, the actual game parts seem to run ok.

My laptop just has the codecs that windows came with plus videolan player installed, are there any codecs that are vital for playing computer based movies? DivX codec is installed as well, now I think about it.