I have Adobe Premiere Elements 12 for Windows Vista. It has been working fine until recently. Now when I click to start it, nothing happens. If I open task manager, it says that it's running, but there's no welcome screen, nothing. The icon doesn't show up on the taskbar.
Premiere Elements 12 on Windows Vista (is that 32 or 64 bit)? Have you updated 12 to 12.1 yet using an opened project's Help Menu/Updates? If not, please do so.
Does the problem exist with or without the antivirus and firewall(s) disabled?
Do you have the latest version of QuickTime installed on your computer with Premiere Elements 12 and are you running the program as administrator?
Is your computer's video card/graphics card driver version up to date according to the web site of the manufacturer of the card?
When you find the program running in the Task Manager/Processes, do you right click its listing and select End Task and then try to start the program by double clicking the desktop icon? Are you working with a dual monitor set up?
With your Windows Vista computer, can you find the Adobe Premiere Elements.exe file, right click it and select Run As Administrator, and then then double click Adobe Premiere Elements.exe to open it?
Please review and consider and then we can decide on troubleshooting strategy.