I bought a new computer and downloaded my lightroom 4 to it. When I installed the program it asked for my serial number and I imputed it. Then it asked for my previous serial number from my original lightroom 3 purchase. Since I upgraded to lightroom 4 I don't have the serial number for the version 3. How do I get the serial number from my 3 version so I can activate my version 4 program
If you have Lightroom 3 still installed, you can get it from there.
If you don't and you have your box/disk, it should be on there.
IF you don't have either of those,and you registered your software, you can log into your Adobe account and retrieve it there.