The Windows 7 compatability site says the drivers are compatible with 64-bit:
http://www.microsoft.com/windows/compatibility/windows-7/en-us/Details.aspx?type=Hardware&p=Samsung%20CLX-6200FX%20All-in-One%20Printer&v=Samsung&uid=CLX6200FX&pf=0&pi=0&s=CLX-6200FX&os=32-bit
However this was my chat with Samsung support:
Please wait for a Samsung Agent to respond.
You are now chatting with 'Joseph'
Joseph: Hello, I am a Samsung Technical Support representative. How may I assist you today?
Visitor: Hello, does the Samsung CLX-6200FX printer work with Windows 7 64-bit? I see 32-bit drivers, but I don't explicitely see 32-bit.
Joseph: Let me check.
Visitor: Thank you
Joseph: There are no Drivers for Windows 7 64 bit but you can can try 32 bit drivers and check if they work.
Visitor: Ok, thank you.