My Computer wont pick up discs?

Alright, so today i went to burn some music onto a blank cd (memorex cd-r 52x 700mb 80 min) and my computer wont recognize it. this is happening with other cds too. i will put them in the drive and for 2 seconds i hear a little noise (the noise you usually hear), but nothing happens. nothing pops up, it doesnt take me anywhere, nothing. please help?