complete removing of a C# COM component

[C# Programming]

Hi all
maybe you can help me a little bit with COM component developed in C#.

I created one C# COM component to provide Excel with some functionality I needeed.

Everything was fine until I did some change to the assembly.
In the new version I did the following:
-I used the same GUID of the old version
-I used using the same strong key name of the old version
- I changed the Assembly version to 1.0.0.0 to 1.0.0.1.
- I registered the assebly in the global assembly cache with gacutil.

Since then Excel is not able to work anymore with this Com and doesn't recognize the library classes.

I tryed to cleanup of my system so I did:
-removal of the library from the GAC
-removal of the typelib
-reinstall of everything from scratch

at the end nothing improved!http://www.barakasoft.com/script/Forums/Images/smiley_frown.gif
What can I do to a perfect clean up of my system?
Some tool or some registry key or value to see?

Thanks in advance
ManuStone