This is not Adobe support, only a forum for users to help each other... so a link to Adobe is all I can provide for a serial number issue... where/what did you buy... discs or downloads?
Serial number and activation chat support (non-CC) may help
On what computer operating system are you trying to install Photoshop Elements 12 and Premiere Elements 12? For now I will assume Windows 7, 8, or 8.1 64 bit.
Did you purchase these programs from Adobe direct as online downloads? Are you trying to install them one at a time with antivirus and
1. Go to Control Panel/Programs and confirm that these programs are not listed under installed program.
2. Make sure
a. anti-virus and firewall(s) are disabled
b. do a ccleaner run through (regular cleaner and registry cleaner parts)
c. install Premiere Elements 12...if any problems, please look at
Assure that you are running the program from a User Account with Administrative Privileges and with Run As Administrator applied (see right click of desktop icon)
Be sure to have QuickTime (latest version) installed on the computer with Premiere Elements 12.
Also, we might delete the Adobe Premiere Elements Prefs file or the whole 12.0 Folder in which it exists....but that is on hold for now.
Also, we might create a new User Account with Administrative Privileges and install and run program there....but that is on hold for now.
If you want to do your own looking at the Event Viewer - right click Computer listing, select Manage, Event Viewer, Windows Logs and Application under Windows Logs. Look for an error or warning that appears related to the time and date of your failure event.
Please review and consider.
We will be watching for your follow up.
Add On...Once Premiere Elements install is successful, then we will move on to Photoshop Elements.