So many problems i don't know where to start

Ok so this all started the other night, i have had this current PC for about a year now and have had no problems with it up until the other night it froze up when i was playing WoW and i was forced to reset it upon restarting it took me to the regular "windows was not shutdown properly last time blahblah" screen, when i selected the windows repair option i was hit with another msg that said,

"Windows has encountered a problem communicating with a device connected to your computer.This error can be caused by unplugging a removable storage device such as an external USB drive while the device is in use, or by faulty hardware such as a hard drive or CD-ROM drive that is failing. Make sure any removable storage is properly connected and then restart your computer.If you continue to receive this error message, contact the hardware manufacturer."

Being the complete computernoob that i am i just reset my PC again and everything seemed fine for about a day or so then this morning when i turned on my computer i was sent to a similar error screen with the msg "Reboot and select proper device or Insert boot media in selected boot device" ...once again me being me i reset the computer a couple of times and had the same msg appear each time so i left the PC off for about 15min and turned it on 1st try without and msg's from the boot screen.

i'm just wondering if there is anything i can do to stop this from happening again also if it helps it seems my CDrom drive isn't responding the icon isn't in My Computer and it wont read the Windows 7 disc i put in there.

well if you got this far thanks for reading my wall of text, i'm not sure how much help you guys can be since i really don't know much about PC's myself but any tips or help is much MUCH appreciated.