Hello!

Question is why my photoshop cs4 looks like that ?

I'd say ur photoshop file is corrupt..
If it's not the file but ur photoshop, try re-install it n check.
(btw, word of a mouth, hope ur CPU is strong to support it )

start Photoshop again but this time right after you have started it press and hold these buttons

Shift +alt + ctrl
it will ask you to delete files say yes, * trust me
then on the next popup say no and you should have your photoshop back to normal

or it might be a graphic card problem it might be over heating

glac