According to the table in the Wikipedia article (see related link) - the maximum supported RAM is 4GB.
Depending on which version of Windows, or Mac you use it can be between 1 and 2 GB of RAM needed For Windows 7 it is usually 1 GB of RAM, and if you use Mac then you will need 2 GB
Yes, you can.
The minimum requirement for RAM to run windows 7 is 1 gigabyte (GB) RAM (32-bit) or 2 GB RAM (64-bit).
1 GB recommended
You can run Windows 7 with 1-2 GB of RAM depending on what you are doing. (More stuff you need more RAM) I Would go with at least 4 if not 8 GB of RAM to run Windows 7.
No>It is not capible with windows 7 because the processor is less the 1 GHz and it has less than 1 GB of ram.
You can, it is possible, but i wouldn't, you probably wont enjoy the user experience.
No, your laptop does not need 4GB of RAM to run Windows 8. The basic specifications for Windows 8 is 2GB for 64-bit or 1 GB for 32-bit. 4GB would help with the processor but would not be necessary.
Windows XP can use any amount of RAM, there is no exact amount. The minimum is 256 MB, the recommended is 512 MB, and the best is 1 GB +.
It doesn't depend on the amount of RAM, it depends on the graphics card. Low amounts of ram with windows aero will only cause the computer to freeze frequently.
Theoretically it should but you might see some lagging in performance. Especially if you have 1 Gb of RAM. Windows 7 needs at least 4 Gb of RAM of you want to feel comfortable working with it.