You'll get better answers on that in the PS forum or PSE forum and when you do, by all means provide some more info liek what version of PS/ PSE, what Mac and so on.
Moving discussion to the Photoshop General Discussion forum.
One of my Macs Died and after changing macs my photoshop wont open please help.
Yep, that was clear as mud all right. Please follow Mylenium's advice and provide more info.
Without knowing more than what you've written: