Now, of course, we have Microsoft's latest operating system - Windows7. It's certainly full of improvements over Vista. The two most common versions are Windows7 Home Premium and Windows7 Professional. Business clients will want Windows7 Enterprise and for the "techno" homeuser who loves the whole nine yards and wall to wall multimedia, then Windows7 Ultimate is the way to go.

Then there's either 32bit or 64bit flavours to consider as well. 64bit is the future especially if your other hardware peripherals (like scanners, printers, webcams, etc.) are recent purchases. Many manufacturers aren't supporting their older offerings with 64bit drivers.

Be aware though, if you're currently running XP, you can't upgrade it to Windows7. You would have to do a complete "clean" install. You could upgrade from XP to Vista, then to Windows7, but the time and cost involved is hardly worth it. If you're currently running Vista - you can use a Windows7 Upgrade.

The primary consideration when selecting components is to ensure as much "future proofing" (upgradability) as possible for a given budget. This also depends on what you want to use the computer for. If it's just Internet surfing, email and some word processing (ie: letters, business documents etc.) then you don't need a superduper machine but it still needs to be fast enough to cope with present and future programmes.

If you are into "gaming", offline or online, then you do need a machine with "grunt" - particularly in the CPU (Central Processing Unit), RAM and Graphics areas. These don't come cheap of course but can be immensely satisfying - especially when the computer "waits" for you rather than the other way around.