Do not install Windows 95 and 98 in a multiple boot configuration. Windows 98 is an upgrade version of Windows95 so it will try to use the same boot file.
When you are installing Windows 95 and Windows 2000, you should always install Windows 2000 lastly because the files necessary to start Windows 2000 could be overwritten. As a golden rule always install the high end operating system at the end. There is no such complication with Windows 98 or 2000; you can install in any order but it is a best practice to install the high end operating system in the last.
If you want to install Windows NT and Windows 2000 then you must install service pack 4 for Windows NT. Windows 2000 is NTFS 5 and Windows NT is NTFS 4 so it will not read 2000 partitions.
You cannot share the application programs in dual boot. The applications must be installed on both operating systems.










