my husband mistakedly erased my windows7 operating system. This is a new computer I have only had it 3 months, and I would think there is a way to get the system back without purchasing a new software package
It sounds like you weren't supplied with any rescue disks. Normally there is a facility to make these, but I'm guessing that you didn't do so. As I see it, you now have two alternatives. 1) purchase recovery disks from the manufacturer of your computer (typically they charge $20-$30 for this) and try to recover the system yourself, or 2) take the computer to a shop, or get a guy in, to see if recovery is possible.
I would tend to go for 2, unless you know what you are doing. It is possible that the OS hasn't been wiped but is merely not working right now; any competent repair man will be able to put this right.