Help with Windows 7 Installation?

OK, I have a Samsung Laptop. The laptop has 4gb RAM The laptop came pre-installed with Windows 7 Home Premium 32bit The laptop does not recognize the full 4gb RAM I want to run Windows 7 Home Premium 64bit So two questions: 1) Will my Windows 7 Home Premium 32bit product key activate Windows 7 Home Premium... show more OK,
I have a Samsung Laptop.
The laptop has 4gb RAM
The laptop came pre-installed with Windows 7 Home Premium 32bit
The laptop does not recognize the full 4gb RAM
I want to run Windows 7 Home Premium 64bit

So two questions:
1) Will my Windows 7 Home Premium 32bit product key activate Windows 7 Home Premium 64bit (bearing in mind I will do a clean install so I won't be running 2 versions of Windows)
2) Will I be able to get a Windows 7 Home Premium 64bit disk from Windows/Samsung to use with my original product key?

Thanks soo much all :D
Tom Fisher
Update: My laptop is compatible with 64bit. Normally if you buy a computer/laptop it comes with installation disks and you can choose whether you want 32 or 64 but 32bit was preinstalled.
3 answers