i will try to attach the images again. if you do not see them send me an e-mail address that i can send them to directly.

when starting Excel:




when a tool bar button is clicked:






to answer your other questions:

1) What version of Excel are you using and what version of Windows? Excel 2003 windows XP
2) Do you have user privilege to install software?
yes
3) Have you successfully installed other Excel Addins?
never tried
4) Re-install XLC
did it
5) Do you have a directory called C://program files/XLC and what files are contained there?
ST6UNST.LOG
XLC.dll
XLC.xll
6) Do you get a "#NAME?" error when you insert the formula "=OVD(1)/UND(2)"
yes