Every Windows Distribution is writen in binary non Open Source files. By the way, there are different versions of Windows Vista: Windows Vista 64-bit and Windows Vista 32-bit. Windows Vista 64-bit or...
Yes, Allmost every Windows Distribution has default navigation or other optional panels in the Explorer Window, You can disable all of them if you want.
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.