d3d9.dll is missing

You should run SFC scan to fix .dll error.

System file check (SFC) is a utility built into the Operating System that will check for system file corruption. The sfc /scannow command (System File Check) scans the integrity of all protected operating system files and replaces incorrect, corrupted, changed, or damaged versions with the correct versions where possible. When it cannot repair the damage, DISM should be run to fix as many errors as possible.

1. To Run SFC (Time required - 5 to 15 minutes) -
Type cmd in Windows Start Search box
Right click on cmd
Run As Administrator
Type or copy / paste sfc /scannow and hit Enter
When you have finished it will say one of three things
a. Windows did not find any integrity violations (a good thing)
b. Windows Resource Protection found corrupt files and repaired them (a good thing)
c. Windows Resource Protection found corrupt files but was unable to fix some (or all) of them (not a good thing - DISM needs to be run)

(It may also give the message - Windows Resource Protection could not perform the requested operation. Then you need to run SFC in Safe Mode. Safe Mode - https://support.microsoft.com/en-us/help/17419/...)

Reboot your computer after SFC finishes

Note - You may have to run SFC up to 2 to 3 times to fix all problems

2. Run DISM (Time required - 15 to 30 minutes) - If you get message - Windows Resource Protection found corrupt files but was unable to fix some (or all) of them, then you need to run DISM
Type cmd in Windows Start Search box
Right click on cmd
Run As Administrator
Type or copy / paste following and press Enter
DISM.exe /Online /Cleanup-image /Restorehealth
Reboot your computer after DISM finishes

Note - After running DISM, it is a good idea to re-run SFC /scannow to make sure all the issues were fixed.

If you get the error message cannot find source files you need to have an ISO file mounted and need to specify where it is located with the below command
(The ISO must be exactly the same version as the running OS. An ISO of 10586.0 will not repair a running system of 10586.35 because it has additional updates and files)

DISM /Online /Cleanup-Image /RestoreHealth /source:WIM:X:\Sources\Install.wim:1 /LimitAccess Where X is the drive letter where the ISO is located. Simply change the X to the correct drive letter

If you do not have an ISO you can make one. The instructions are @ https://www.microsoft.com/en-us/software-downlo...

Give these a try:
Method 1: I would suggest to re-register the .dll’s:

1. Click on Start, then Run.

2. Now all you have to do to register a DLL file is to type in the regsvr32 command, followed by the path of the DLL file. : regsvr32 C:\Windows\System32\D3D9.dll

3. Hit OK.

Method 2: If the issue does not resolve run system file checker.

Sometimes this kind of unexpected behavior shown by Windows due to some missing or corrupt important system files. I would suggest you to rum Microsoft Safety Scanner SFC /SCANNOW to scan the system integration and fix system file corruption (if any).

The sfc /scannow (System File Checker) command scans all protected system files, and replaces incorrect versions with correct Microsoft versions.

Use the System File Checker tool to troubleshoot missing or corrupted system files.

http://support.microsoft.com/kb/929833/en-us

Method 3: If the system file checker unable to repair corrupt files try to follow clean boot process and check the issue.

Try to clean boot the system and check the issue.

A clean boot is performed to start Windows by using a minimal set of drivers and startup programs. This helps eliminate software conflicts that occur when you install a program or an update or when you run a program in Windows 8.1, Windows 8, Windows 7, or Windows Vista. You may also troubleshoot or determine what conflict is causing the problem by performing a clean boot.

How to perform a clean boot in Windows

http://support.microsoft.com/kb/929135

Note: Refer "How to reset the computer to start normally after clean boot troubleshooting" to reset the computer to start as normal after troubleshooting.

Method 4: If the issue still does not resolve try to run Microsoft safety scanner.

Run Microsoft Security Scanner as there can be possible virus on the computer

http://www.microsoft.com/security/scanner/en-us...

Note: Any data files that are infected may only be cleaned by deleting the file entirely, which means there is a potential for data loss.

Method 5: If the above steps did not resolve the issue follow the steps given below.

Refer the Vinod N replied on October 17, 2010 on microsoft forums.

http://answers.microsoft.com/en-us/windows/foru...

If none of the above help, perform a repair upgrade:

http://answers.microsoft.com/en-us/insider/wiki...

Thanks. sfc ran with errors so I had to run DISM then when I re-ran sfc for a second time it completed successfully. After a reboot the error was no longer seen

Thanks for your help