What computer operating system is it running on? For now I will assume Windows 7, 8, or 8.1 64 bit.
Does the problem exist with and without the antivirus program disabled?
Because of the circumstances that you described, I would consider Premiere Elements 12 and QuickTime uninstall (the usual Control Panel route).
Then a free ccleaner run through (regular cleaner and registry cleaner parts) to get rid of leftovers. CCleaner - Download
Then reinstall QuickTime and then Premiere Elements with antivirus and firewall(s) disabled.
Any questions or need clarification, please do not hesitate to ask.