You can use software such as Acronis True Image or Disk Director to backup your partition(s) (operation system and personal data files) to another hard drive. However
, you can't boot into the backed up operating system on another system, because the backed up operating system won't have the correct drivers installed for the different hardware devices in the new system. It will fail to boot.
Of course, if the second system has exactly the same hardware devices installed, then theoretically it will work. To add, on rare occasions, you can boot into an OS on a hard drive taken from another system, but usually not without complications.
What OS are you using on your first and second systems? Windows Easy Transfer
allows you to '...move the files and settings stored on your PC running Windows 2000, Windows XP, or even Windows Vista to a new PC running Windows Vista.' It can't transfer installed programs, but it can transfer program data files. I haven't used it myself, but it's an option.