My nokia c3 keeps freezing when i turn my phone on

SOURCE: i want to watch movies

Try updating your phone's firmware. Also, check your video file and make sure it isn't too big. Cell phones have limited resources and movies with big resolutions sometimes are too demanding.
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SOURCE: My Nokia C3-01 keeps freezing, can't log in to get

This solution should help fix the issue. I advise you use the Nokia PC Suite to backup your phone data prior to doing this reset. Also, you should download and install Nokia Software Updater and use this to update your phones firmware and software in the future.

1. Enter *#7370# code from the keypad. and press the Dial button.
2. Type unlock code 12345 press continue.
3. Restart your phone.
4. You should check for updates on the phone at this time Enter *#0000# from the keypad and press the dial button
5. Select "Options" and then select "Check for updates".

SOURCE: My nokia c3 cell phone has a camara malfunction,

For Camera hang ups or frozen if using it, this problem can be fix by firmware restoring, flashing or updating. So try to do a software repair first before proceeding to hardware troubleshooting.
If the camera doesn't turns on or having problem like showing empty or black screen, this is due to problem in hardware.
For instructions to update firmware, please check following link.
Nokia C3 Software/Firmware update

for more help about nokia c3 troubleshooting, click here