Try these steps:
First, make sure you've installed CB2025 on the new computer.
Next, follow these steps to transfer your database from your old computer to the new using a USB thumb drive:
Launch ComicBase on your older computer and make sure your main database is loaded in
Next, Go to the File > Save a Copy to save your database to the USB thumb drive. Give your database a new unique name so its easy to locate (ex: Dan's Comic Collection).
Onced saved, safely remove the USB thumb drive from the older computer.
insert the USB thumb drive in the new computer,
Locate the database file on the thumb drive and copy it over to the following folder location: Documents \Human Computing\ComicBase Databases folder
Once the database has been copied, double-click on it and it should automatically load into ComicBase 2025 on the new computer
If you're still stuck and not able to proceed, feel free to give our tech support team a call at 408-266-6883 (M-F, 9am to 5pm PST)