Reply to Windows CPU question.. upgrade windows or upgrade the laptop?

Hello,
Long time lurker first time poster.

Currently running an S4 on vista. Laptop is a gateway P 7805u.

Intel Centrino 2 2.26GHz processor.
4GB RAM.
17" WXGA high-definition widescreen.
VIDIA GeForce 9800M GTS.

I've done about all I can optimization wise, its pretty barebone. All drivers are up to date. I still get crackles and dropouts around a few times per hour. Granted, its doable for house parties and small groups when no one really cares, but I can't go any farther with this setup. This is a dedicated djing laptop.

So to my question, will upgrading to windows 7 provide me with the system stability that I need. Or is this computer just too slow to handle the S4. I don't want to waste the 100-150$ on Windows 7 just to find out I need to upgrade laptops anyways.

If not, any suggestions on a windows based laptop preferably less then $1000 that would give me the best bang for my buck as a dj only machine?