Any amount will be fine in Windows and Mac. However, with lower amounts of RAM, you may need to run older versions of Opera.
The RAM is where the computer stores all the required codes to run it.
Windows XP can never "run like Windows 7", regardless of the amount of RAM installed.
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.
This speaks of RAM. Required memory is 64 MB. Recommended is 128 MB and the OS supports up to 4 GB.
Windows Vista will run on a computer with a minimum of 512 MB of RAM
A software which need 2GB RAM will may run with 512MB RAM [Not in a perfect way]. Today computers use virtual memory for multitasking [for running more programs at the same time]. An over-reliance upon virtual-memory can slow overall system performance. By enabling the virtual memory feature, you are asking the computer to use a part of the Hard Disk as Physical Memory [RAM]. Always remember that the Hard Disk is much slower than the original RAM. In this case, you are asking the computer to find the remaining 1.5 GB of RAM which is required to run the software from virtual memory and this will result in constant disk swapping or thrashing which will slow down your computer considerably. So, it is clear that 2GB of RAM is required to run that software in a smooth way and that is what the software developer want to see. That is why the minimum RAM required to run the software is set to 2GB.
The recommended amount of RAM memory is about 1 gigabite although 2 or 3 gigs is good for a smooth framerate
To run windows 7 you need at least 4gb of ram
No, Opera's servers run on Linux.
To use windows aero in vista operating system 512 mb of ram is required
It is highly unlikely, since most mobile phones do not have the required hardware to run Flash.
The operating system is not directly related to the amount of RAM installed. XP can be run on anything from 32 MB of RAM to 4 GB.