Direct X 9c Problem

[n0ah]

Atm I got DX 9b. When I try install DX 9c, installation runs as usual, then it shows installing progress (installation time varies from few seconds to 10 minutes (with same setup file)), then it finishes and writes: "The components installed are now ready for use". But actually no changes were made
My System:
Operating System: WinXP Professional 5.1 SP2, v.2096 (Build #2600)
CPU: Intel Pentium 4
Video: NVIDIA GeForce PCX 5900
Sound Card: Realtek HD Audio

[Drool]

Maybe the file u downloaded is corrupt - try downloading it twice.

[Torque]

Maybe it's already been installed on your system.

[n0ah]

Maybe the file u downloaded is corrupt - try downloading it twice.

I tried every setup I could found, still same.

Maybe it's already been installed on your system.

run -> dxdiag -> DirectX Version: DirectX 9.0b (4.09.0000.0903)
Its really anoying. I downlo... *cough* I mean bought many new games and programs (F.E.A.R, CoF 2,Vegas) that uses 9c, but I cant use them  

[Paxton]

Is your windows.. how to say.. healthy?

[n0ah]

Here is what I tried: Reinstall windows, format hard drive, scan my PC with 6 AV programs, update drivers, uninstall DX. Nothing helped

[JayFoxRox]

ehhh i doubt you formated your hd cause it would have installed fine then, dx is only an layer not a full hardware "driver" so it will only start when you use it.
Make sure you have a "real" windows, remove FW, check if theres enough disc space on c:/, make sure you close all programms using directx - i recommend to kill 90% of all process in the taskman, you have a checksummed download of it. And check if your card has full or only emulated DirectX9.0 support