Q: iMac locks up on restart and will not complete start up

Try resetting the PRAM 2-3 times and then attempt to restart normally.

Intel iMac SMC and PRAM resets

Updated safari os x version 10.9.5 cant get passed password . no access need help also

Try reseting the SMC, as per > Resetting the System Management Controller (SMC) on your Mac - Apple Support

Then startup holding the Option key to see if it will startup into the Startup Manager.

If it does, try selecting your Macintosh HD startup volume to see if it will startup normally.

If it does not startup from your Macintosh HD, start over in the Startup Manager and select Recovery.

If it starts up in Recovery use Disk Utility and try to repair your Macintosh HD and try a normal Restart.

If none of that works, them make an service appointment at your local AASP or Apple Store.

see > https://locate.apple.com/

Natemaquez,

Please create your own thread, you may not know it but what you are attempting to do is called thread jacking and is considered rude. I am sure you are not trying to be rude though.

Good luck and I am sure someone will be willing to help you.