Longhorn
user name and password
Windows XP and Windows 2003 came before Windows Vista. The 64-bit version of XP was really mostly Windows 2003 branded as XP, and not truly XP, despite the name.
Windows 3.0 is not a version of Windows available for the Windows Vista GUI. Any version of Windows before Windows 2000 are also not available.
All service packs
You should buy an upgrade version of Windows Vista however your computer if running XP is likely not to be powerful enough to run windows vista. You should run Microsoft Windows Vista Upgrade Advisor before upgrading as this will show you any problems your computer may have running Vista.
Windows vista came AFTER windows Xp, however it was announced by microsoft to be a massive failure and its production stopped due to software issues.a
It was codenamed Longhorn.
Vista is just a version of Windows; the version after Windows XP and before Windows 7. If a machine is Vista-ready or Vista-compatible, it just means that the hardware and available drivers are compatible with Windows Vista. You might be able to run that PC on Windows 7 or 8, but it depends, and you would have to check with the manufacturer to find out what all it is compatible with.
That edition of Windows Vista does not exist. Windows Vista exists in two editions for home users: Windows Vista Home Basic and Windows Vista Home Premium.
No your windows 7 will not deleted
No. Obviously, if you upgrade to Windows Vista, you will have Windows Vista.
No.