How can i play my assassins creed PC game because every time i put the CD in and want to play the PC says Please insert the correct CD-ROM select OK and restart application

Your problem may be caused by a couple of different things. Firstly, you should be sure that you have the correct CD inserted in the correct place. Perhaps your computer has multiple CD drives, and it is searching in a different drive to where you have inserted it. Also, make sure you have the right CD inserted - if there are multiple CDs required to install it you should make sure the disc marked "Disc 1" is inserted.

If you've followed all of that and you still have the problem, then your computer isn't recognising, the disc, which means there may be something wrong with your computer (which you would know if you also have problems with other CDs), or there may be something wrong with the disc. Was it a pirated copy? Is the disc scratched? This kind of thing could be the cause of your problem.