ActiveX error appears in Outlook after you just edited your signature
Go to C:\Documents and Settings\USERNAME\Application Data\Microsoft\Signatures
Make a backup of the files that are in there.
Edit the .htm version of the signature in notepad (Don’t use Word as that’s what creates this problem in the first place).
Look for an Object tag, for example:
OBJECT id=ieooui classid=clsid:38481807-CA0E-42D2-BF39-B33AF135CC4D>
And remove it. Now save the file. Open Outlook and start a new e-mail with your sig in. The ActiveX error should now have gone.
UPDATE:
If the user has redirected folders on then their signature will be on the server like the following:
\\SERVERNAME\SHAREFOLDER\USERNAME\Application Data\Microsoft\Signatures
May need to make hidden folders visible.