If your laptop is like mine, Windows is sitting on all the available primary partition space (for that reason, of course), and you need to delete one of the primary Windows partitions (choose wisely! Don't choose the Windows loader partion if you want to dual-boot) to be able to create a Linux partition (that partition you can then split into as many secondary partitions as you want).

If this isn't enough info, use a Linux/GParted cd/dvd to post a screenshot of your drive(s) :)