Excel Assistant (Paperclip Icon) Question

[Jake]

This is not a very important question, don't need an answer fast, etc.
BUT, I can't change my icon from the paperclip to the puppy dog.
Clicking on the icon gives me a menu, including "Change Icons". When I click this I sometimes I get the error message "Not Enough Memory for This Operation" or some such. Sometimes nothing happens.
I've even re-installed Excel, but to no avail. My computer (Dell 1501) has plenty of memory left, and I'm left puzzled.
Help! I want my puppy dog back!