You might be interested to know that Windows keys don't discriminate between 32-bit/64-bit. If you can find installation media for the same type of x64 distribution (Home, Pro, etc) as your 32-bit, you can install x64 and use your current key. May be worth the reinstall to get access to your RAM.
Of course, you might make sure that appropriate drivers for your laptop exist for x64. I would hope any laptop that can accommodate 8GB would have x64 drivers.
Of course, you might make sure that appropriate drivers for your laptop exist for x64. I would hope any laptop that can accommodate 8GB would have x64 drivers.