If you have to redownload Dolphin everytime it fails, then something may be changing the original exe (virus?). This is not a normal behavior for any program, I don't think Dolphin is the cuase. Also try to run it as administrator if you are sure you are virus free.
never got solved currently downloading the next version will let you know if its fixed.
Did nothing, ive noticed now that Dolphin.exe. is sometimes still open after the first attempt running in task manager but if I stop the process I still cant open it.
Try:
-Restarting Dolphin
-Updating To the Latest Dolphin 3.5 Release
(
http://dolphin-emu.org/download/)
-Updating your graphics card drivers
-Also maybe try restarting your computer?