Windows 7 is the eighth (yeah I said 8th) major version of Windows. Windows 7 is the eighth in a line of Microsoft Windows operating systems. There have been: Windows, Windows 3, Windows 95, Windows 98, Windows ME, Windows XP, Windows Vista, and Windows 7.
You may have also heard of, if not used Windows NT or Windows 2000, but they were a different breed designed specifically for the corporate high-security/high-reliability market.
When Windows XP was introduced (2001), Microsoft merged the two streams. Windows XP was a clear winner. Still felt by most to be more than adequate. Vista had some initial problems which were fairly quickly fixed with the subsequent service packs 1 and 2. It is actually a good operating system which unfortunately developed bad press due mostly to some very misleading, if not dishonest advertising from Apple.
Windows 7 is really service pack 3 for Vista but with a new name that has not been saddled with the undeserved reputation of Vista. It’s always important to install service packs when they come out and I will advise you when that happens.
Upgrading to another operating system is almost never a good idea. Techies will advise you that the only way to install a new operating system is to erase the hard drive and install from scratch.