HANDS ON GUIDE

Vista OEM

If a deal looks too good to be true then there's a good chance that it is. Your mother probably told you that, and you should always listen to your mother. When Vista was still on pre-order, and the astronomical pricing of the top versions was becoming evident, the perennial question of buying a much cheaper OEM copy came to the fore even more strongly than it had with XP. Builders of PCs are able to buy their copies of Windows much more cheaply than end users. Originally, this only applied with operating systems supplied with ready-made systems, but the growth in self-building meant that vendors started supplying these copies of Windows with components. This was particularly necessary with the Media Center Edition of Windows XP, as there was no retail version.

You can now buy an OEM copy of Windows without needing a hardware purchase to accompany it, although in theory, it's supposed to be supplied with a 'fully assembled computer system' or 'non-peripheral computer hardware component', according to Microsoft's EULA. The prices are very tempting too. For example, Scan sells the retail edition of Windows Vista Home Premium for £195.01, and Ultimate sells for a gob-smacking £316.08. The upgrades are respectively £129.24 and £215.25, but the OEM versions are just £68.73 and £109.26.

However, as we hinted earlier, all the best deals come with strings attached. Windows XP OEM limited the number of hardware changes that could be made before activation was required again, and this caught out enthusiasts who constantly swap out hardware in their PCs. OEM Vista is the same. In particular, OEM versions of Windows are only for one PC, whereas retail editions are transferable, so long as you remove them from the old system first. No formal checks are performed, however. A motherboard upgrade is considered a new PC, and leads to telephone activation, where you'll be told to buy a new copy of Windows. There are reports that Microsoft is kind to those claiming their motherboard died and needed replacing, allowing activation over the phone for one motherboard change, but this isn't guaranteed. You also can't return an OEM copy of Windows once you've opened the packaging, whereas you can send back a retail copy.

The Windows Product Activation (WPA) system also tracks ten categories of hardware for any changes: the graphics card, the motherboard EIDE/S-ATA controller, any SCSI adaptors fitted, the network card and its MAC address, RAM amount, processor type, processor serial number (if enabled), hard drive, hard drive volume serial number, and the make and model of optical drive. The tracking system uses a complex tally of 'votes', whereby some devices receive more votes than others if they remain unchanged; for example, the network card has three. If seven or more unchanged votes are registered, no reactivation will be required. Essentially, the same WPA system remains within Windows Vista, so if you keep the same motherboard and processor, you can probably upgrade most other parts without reactivation on an OEM copy. However, it's also worth noting that the retail and upgrade versions of Windows Vista include both 32- and 64-bit iterations, while the OEM versions are either one or the other.

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