No. A Duron does not support AMD64 instructions, which are necessary to run a 64-bit operating system.
Yes. The Intel Pentium Dual-Core is a 64-bit processor.
The graphics processor should already be in use if your driver is installed. if the driver is not installed then you can download and install it from the respective processor brand.
Yes. Windows 7 will run on a computer with an Intel Atom processor.
On the internet (preferably Google), search for and install "Advanced Windows Care 2 Personal". When you open the program, there is display of your OS, processor info, Graphics card, and ram. Also you get your computer optimized for free.
No. Windows XP will not run on a computer with a 486 processor.
If you have had your computer since Windows 95 then it probably does not have processor speed and RAM that will give you an acceptable experience if you install Windows XP on it. If you want to try anyway I suggest a complete disk format (after saving to another medium any files that you could conceivably want to access later). the install Windows XP.
Yes, you can.
Yes.
Windows Vista Ultimate
Ultimate and Enterprise
The manufacturer of your processor does not matter as long it meets the minimum requirement of your operative system.
You should be able to install ether or even both.
Yes.