Registry fixers in general are not a good idea. They take a shotgun approach to the registry and remove things according to predefined patterns that are sometimes faulty, leading to removal of needed entries and loss of functionality. Any real "errors" in the registry need to be repaired manually. The only registry tool I recommend is a registry compactor (sometimes called a "defragger") such as the free registry defragger from
www.auslogics.com .
The file you found is the one that the error message claims is faulty. We still need to find a new copy in order to replace it. So, take a look at your firat recovery CD and see if there is an i386 folder on it.
If you find i386, then put the CD in and close any windows that pop up.
Go to Start > Run, and type:
expand D:\i386\imm32.dl_ C:\Windows\system32\imm32.dll
(adjusting the drive letters to your system if D: is not your CD-ROM or C: is not your system drive).