There are several barriers on hard drive size for Windows ME. As it relies on the BIOS for addressing, it suffers from the same limits on hard drive size as the BIOS. Here are the important ones:
127 GB barrier (hardware) - Most PCs of the era that Windows ME was released do not support more than 127 GB hard drives - the extra capacity will be unusable.
127 GB barrier (software) - Windows ME itself cannot address more than 127 GB natively. There are special patches that will allow it to address more. You will also need to use a third-party tool to partition the disk.
2 TB barrier (FAT32 implementation limit) - The FAT32 file system as used by Windows ME cannot be made larger than about 2 TB. However, you can divide the hard drive into partitions, so you should still be able to use disks larger than 2 TB. At this size, the limitations of the FAT32 file system really start to come into play, and defragmentation will take several hours.
The minimum requirement to run Windows Millennium are as follows: Pentium 150MHz Processor 32MB of RAM 320MB of hard drive space
There is no upgrade path from Windows ME to Windows 2000. You would have to reformat the hard drive to remove ME before you install Windows 2000 from scratch.
Windows xp supports a maximum of 4 gigabytes of ram and 2 Terabytes of hard drive space
Yes, you certainly can. Install Windows Me first on one of the hard drives. And after that install Vista on another hard drive. If you do reversed multiboot will not work. And you will have to edit boot.ini file manually which is not that easy.
maximum number of partition that can be created on a hard drive?
The current maximum size of an NTFS partition is 16 exabytes (18 billion gigabytes). Assuming you can divide up the drive into four primary partitions, you can have 64 exabytes on a hard drive. Of course, Windows still uses BIOS addressing to find the size of a hard drive, so it is still limited by what the BIOS can see. Currently, the newest BIOSes support a maximum of 144 petabytes (144 million gigabytes).
The hard drive stores the Operating System. Like for example : Windows XP or Windows Vista or even Windows 7 without the hard drive your computer will not turn on.
Yes you can have the Mac OS on one drive and Windows on another drive. Or you can partition a single hard drive and have both on the same drive.
Windows XP has no bearing on the hard drive size beyond what is needed to store it. Thus a hard drive on which Windows XP is installed can be anywhere from 1.5 GB to 3 TB.
format your hard drive
During installation, Windows 7 will need about 16GB on a hard drive.