Printer uninstalls automatically

[ixan]

I want to save Excel 2003 files as pdfs so I installed Bullzip. Works great. Couple of days later, I wanted to do the same thing, Bullzip has to be reinstalled. Today, same thing, no Bullzip, have to reinstall again. Can any one tell me what I need to do to keep it installed? I have Vista and Chrome 7 beta.