I'm considering moving to Windows 7 64-bit:
- Will it work faster than Windows 7 32bit?
- Will Oracle 11g & Visual Studio work on it?
- Do I need special hardware? (I have a Dell Latitude D520 laptop)
For many applications, there will be very little difference.
What makes a big difference, though, is that x64 can make proper use of large amounts of memory beyond 3.25 GB.
So if you have 4GB physical memory, you'll effectively get an approx 25% extra free RAM for nothing by moving to x64.
I went from x86 XP to x64 Win7 (on the same machine), so it's not a real comparison. But it feels a lot faster.
Visual Studio 2008 and 2010 work fine.
As for speed, I don't know. Some people note that 64bit programs will be faster because of larger number of registers available, but other say that they will be slower because of larger pointer size. Most of data-crunching programs will be faster in general if they are 64bit too.
I never used Oracle, so I'm not going o comment on that.
As for hardware, you obviously need 64bit processor and computer which will accept it. Nothing else is needed.