My husband did a stupid thing and went and unplugged our RAM to see what kind we had. When he turned the computer on after putting the RAM back in the computer said there was no boot device. This doesn't make any sense to me. Please help!
No 'boot device' would mean no hard disk visible to the laptop.
Can you feel.hear the HDD start to spin up when you turn the power on?
Do you have a bootable CD you can test?
If not you can create a bootable Rescue CD and use that to test if the laptop will boot.
AVG Rescue CD: http://www.avg.com/us-en/226386
The best way to find out what RAM is installed is use CPU-Z.
The Memory and SPD tabs will tell you all you need to know about the RAM installed.