1) Ensure that the "Cryptographic Services" service is running on your computer. To do this, open Control Panel, Administrative Tools, Services. Select "Cryptographic Services" from the list of names. Right-click this service and select Properties. If the service is not shown as "Started", you can start it by clicking the Start button. You should also set the Startup type to Automatic so that it will be running when needed in future. Close the Services control panel and try installing the service pack or security patch.

2) If the "Cryptographic Services" service was already running, stop the service by clicking the Stop button, then using Windows Explorer, locate the folder C:/Windows/System32/catroot2 and rename it to something like xcatroot. Now restart "Cryptographic Services" by clicking the Start button, and try installing the directx.

3) If the directx still fails to install, stop the "Cryptographic Services" service again. Open a command prompt window (click Start, Run, type "cmd", without quotes and hit Enter) and then type the following commands:

regsvr32 softpub.dll
regsvr32 wintrust.dll
regsvr32 initpki.dll
regsvr32 dssenh.dll
regsvr32 rsaenh.dll
regsvr32 gpkcsp.dll
regsvr32 sccbase.dll
regsvr32 slbcsp.dll
regsvr32 cryptdlg.dll

Restart "Cryptographic Services" by clicking the Start button again.