MacBook pro stuck at update screen

[Tsouchet]

I tried updating my Mac to yosemite and it is stuck at this screen .. Not sure what to do it's been like this for hours

 

[yodudears7]

It may sound risky, and can be risky, you may have to hold the power button down and cancel the installation. I have never had an update get stuck, but sometimes they can take awhile.
Again, shutting down mid installation may damage your OS! But thats the only way out that I can think of.

 

[Tsouchet]

It may sound risky, and can be risky, you may have to hold the power button down and cancel the installation. I have never had an update get stuck, but sometimes they can take awhile.
Again, shutting down mid installation may damage your OS! But thats the only way out that I can think of.

I did just that and it worked! it was scary cause i didn't want to damage the OS! but it worked ! thank you