Peachtree 2005 hasn't been supported in 17 years, but the error message "You Cannot Use Peachtree right now because the serial number(s) you have [serial number] are already in use by the maximum number of computers" can occur on current versions of the program as well.

If you're running Peachtree on a standalone computer, the best solution is to reboot the computer, which often clears the error message.  If that doesn't work you can also stop and start the database engine (called Actian Zen in current versions, but Pervasive in the 2007 version).  Despite the name change, the steps for stopping and starting Pervasive should be the same as those listed for Actian Zen here: https://support.na.sage.com/selfservice/viewdocument.do?noCount=true&externalId=10281

Edit: Pervasive was not used until Peachtree 2007.  Btrieve was used in Peachtree 2005.  We no longer have steps for starting and stopping Btrieve.

If neither of those solutions work, then I'd recommend trying the solutions listed in this article for the error: https://support.na.sage.com/selfservice/viewdocument.do?noCount=true&externalId=10897   Solutions are listed from most to least common, and some of them would already be covered by restarting and using an old version, so you can start at Section 3.

Hi Bruce,

Technology has changed since you pruchased your program 17 years ago.  We are still selling the Sage 50(formerly Peachtree TRADITIONAL software) through December 30, 2022.  If you want to upgrade, we can help you.  Please feel free to reach out to me. 

[email protected]   304-233-2612  I am a Sage 50 Certified Consultant.  Our programs come with unlimited Sage support and updates for one year and we have special pricing to help you move your data to the new 2023 software when you purchase the program from us. 

Thank You.  Rebooting the computer seems to have released the hold.  I will keep your reply on hand for any future occurrences.

Hi Bruce, if the above suggested answer helped, please do mark it as verified  (by clicking the "more" button on the response) for the benefit of others in this forum . Thank you!