System Lost my Directx 9c Version

Hi,
I was trying to open FS 2004 by cliking on the icon, but after 5 sec it shows me a window telling me that the version of Microsoft Directx installed is not compatible. It continues saying: try to reinstall Directx 9.0 from the installing program of FS 2004 or on the web site

The point is that, when i try to install the directx downloaded from windows web site, another windows opens when trying to install Directx 9.0c:

A file CAB for installation it's not reliable. Verify that the crittography services are enabled and that the certificate of the CAB is valid.

How can I see what version of directx I need and, after finding it, where shall i put it, in what folder?

Thank you

For the version number you can type dxdiag on your start > run box. There you will get a popup box of direcx settings. At the first page only below it will show you the version of Direct X. For the error thing first go to control panel and uninstall the same completely. Then click on start > run and type regedit. Then go to HKEY_LOCAL_MACHINE\Software\Microsoft\DirectX and remove the direct x. Then re-install the same.