Follow these steps to replace the Riched32.dll file:
1- Search for the file on your hard drive using Start > Search, then enter Riched32.dll (it is typically in the C:\Windows\System32 folder.)
2- Rename the file to Riched32.old. If it gives you access denied message, try booting in safe mode and renaming it from there.
3- Extract a new copy of Riched32.dll by clicking Start > Run, type msconfig and hit the enter key. Click on the General tab, click on the Expand File button, and enter the following:
- In the File to restore box, type Riched32.dll.
- In the Restore from box, type C:\Windows\options\install (assuming your windows folder path is C:\Windows)
- In the Save file in box, type C:\Windows\system, and then click OK.
Hope this will do it for you.
for further reference please visit http://support.microsoft.com/?scid=kb;en-us;322104