Windows ME was written to replace Windows 98. It crashed frequently. People replaced it with Windows 98. Microsoft quickly replaced it with Windows XP, which works much better.
The simple answer is both are based on similar code base, but one is made for business (W2k), and the other for main stream (XP). Windows XP SP2 AND WINDOWS 2000 SP4 are the standard minimum versions...
You can install Windows without a product key and it will work for x amount of days before forcing you to enter your product key. Each version of Windows has its own rules and can work for longer...
No. Windows CE is not typically run on the same types of hardware as Windows XP or Windows 7. There is also no Windows CE version of the setup program on the Windows XP or Windows 7 discs, so even if...