Several problems pertaining to Windows XP

A little background: my work computer was originally operating system Windows Home edition. One day after starting windows and getting a black screen I searched online on another computer and figured out how to fix it and to make a long story short I was able to get back to my old home edition but I installed Windows Professional while doing so. So now I have two operating systems on this computer, both home and professional. After I solved the original issue with the home edition I no longer used the professional edition. So I start up the computer today and select the home edition and I get this message:

"The application or DLL c:\WINDOWS\system32\ShimEng.dll is not a valid windows image. Please check this against your installation diskette."

So after getting that message several times I am now using the professional edition on this computer and I can still access my files but I don't have the virus protection from the home edition because it was an online purchase and we have no disk for it.

If I have to use the professional version it's really not a big deal since I can access all of my docs...so I was trying to update the current version of internet explorer to version 8 and I get the following message:

"The procedure entry point SHRegGetValueW could not be located in the dynamic link library SHLWAPI.dll."

It's just one thing after the other. This computer is like 8 years old and it's definitely time for a new one and has been for a while but since our business has slowed down it really isn't in the budget. I would ultimately prefer using the home edition that I was using all along but if I have to use the professional version, how do I remove the home edition without sacrificing all of my files and how do I install the newest version of internet explorer...and how do I get my virus protection over to professional?

:cry

 

The first step to discard is a Virus, Malware or Spyware.

I suggest that you take a look over the:

READ & RUN ME FIRST

Also you could:

Start > run > MRT (it's the malicious software removal tool from microsoft).

Keep us up to date.:zzz

 

Start, run, MRT doesn't work for me...I will read the other link.

Thanks!