Hi: I am getting very frustrated with this problem. I installed Opera (the free web browser). The appstore reminded me to update it. When I click "update" I get a "To update this application, sign in to the account you used to purchase it." I have not purchased it with another account. I do have only one Apple account for iPhone, iPad and MacPro and that account/Credit Card is valid and active. After contacting Apple tech support I was told to just delete it and then redownload from "purchases". I deleted it but I get the same error. I cannot download Opera as the appstore/computer thinks that it is installed. I asked apple tech support (different divisions and levels) where on my boot drive would be the entry that states Opera is still installed. I have not received an answer. I looked for anything "Opera" related and deleted it (Library/Caches and Library/Preferences..) still no change. I used the hide-unhide program and Finder cannot find anything Opera related. My question to the collective brain trust is: where on my boot drive would be the entry that makes the appstore think that opera is installed? Thanks for any help. sg BTW: Apple tech support told me that they cannot just delete Opera from my account!