"System Error &H80004005 (-2147467259). Unspecified error"

we are on V.4.2 SP4.

One user getting error opening WebExcel which says:

"System Error &H80004005 (-2147467259). Unspecified error"

And when clicked OK, another pop up saying "out of memory"

We had some other users getting this error after installing Excel 2007 and uninstall 2007/reinstall 2003 or one user getting same error without installing 2007 at all.

Then we had to run system restore to the point to before Excel 2007 was installed.

But for this user, system restore was failed.

Does any of you have ever getting same error and resolved without performing system restore?

Thanks,