Upgradation Of Zippy Notes

Hi All

I want to upgrade zippy notes, first of all I Rrmove old version of zippy notes and service pack. But whenever I go for install the new version it give me the message try another time. I try a lot but I could'nt. so please any one can tell me whats wrong there or what should I do for upgradation.And one more thing is that if I install the zippy notes on new computer so it works on there but does'nt work for upgradation. upset so please help me