PC wont start after changing hard disk

[sed]

my PC cannot start after i change hard disk. no power to the PC. i only change hard disk but it caused everything stop

 

[arkadi]

1. Disconnect the power cord, press and hold power swich 4 few seconds.
2. Disconnect the new hd, and double check all connections. Check the PSU switch if you have one.
3. Connect the power cord and try the power switch.
4. If nothing happens, repeat stage one.
5. Disconnect all no essential hardware from the MB and the PSU.
6. Repeat stage three.
7. Next stage depend on your skill lvl, in your case i think it will be better if you will Get it to Computer lab. If you have spare PSU unit you can try it as well.

 

[Winly]

did you disconnect any cables while changing the hard drive? or the computer turn on but doesnt load windows and it gives you an error?