How-To Geek

I've just got a few questions about Windows OS's.

What is the difference between retail, upgrade versions, and OEM? I know OEM is cheaper, but why? What is it?

Also, if I were to get the upgrade version of Windows 7 from XP, how many times could I install it? I've had several problems with my computer and I've reinstalled XP many, many times. Is there a specific version that allows me to do that? Is that the OEM version?

Or, if I get the upgrade version of Win 7, will I be able to install it only 5 (whatever the number is) times? What version would I need to be able to install it more than that?

Is it possible at all to have an OS on two different machines?

Hmm, that's a lot of questions. Let me try to answer them to the best of my knowledge:

1. Retail - is the best but most expensive option. You get the full MS blessings including support. You can install it on any system.
OEM - is essentially the same as retail but you get no MS support. The support comes from the OEM - and if you buy it seperatly from a PC, the OEM is YOU.
Upgrade - that comes in 2 flavors. It can be an upgrade from another OS as will be offered for Windows7 for those that have an XP or Vista. That has to install on the system where the upgradeable OS resides. It is a full operating system. Another flavor is an upgrade from a lower version (let's say Home Premium) to a higher version (e.g. Ultimate). This is not a full system and must be installed on top of the lower system ( usually a real mess).

2. Any system can be installed as many times as you want. That's easy with the Retail and OEM because they are full installation systems. A little trickier with the upgrades because you always have to first go back to the base.

3. An operating sytem can only be installed on one system. Unlike some applications like Norton or Office 2007 which can be installed on 3 systems. The operating system is void, if you switch the system - even if you change the motherboard of your system because the mobo is the system ID. But there are ways to revalidate the OS with Microsoft.

I hope that helps. Maybe other members can add more logic.

OEM is probably the best deal if you do not need the MS support.

I think that is a question to ask Microsoft. This is somewhere deep in the EULA and not obvious. My first intuition would be that you need a full license for a brand new machine. But they have mechanisms where you can uninstall and reinstall - I just don't know enough about those. Example where those mechanisms are applied is when you change the mobo.

@ whs:

"An upgrade or a replacement of the motherboard is considered to create a new personal computer. Therefore, Microsoft OEM operating system software cannot be transferred from another computer. If the motherboard is upgraded or replaced for reasons other than a defect then a new computer is created, and a new operating system license is required."

Guess I can't get the cheaper upgrade pricing for Windows 7 if I build a new PC. That's really stupid. You should be able to de-authorize (or whatever) the motherboard and transfer to a new one.

Thank you for your help.

@ ScottW:

I don't want to call Microsoft and talk to a robot. I think I'll just buy Vista and get the Win 7 free thing. It's much cheaper. Would I have to install Vista to do the upgrade thing, or could I just have it laying around until Windows 7 comes out?

Thank you for your help, ScottW.

Yes, you will have to buy a full price version.
However, I believe there is some kind of preordering thing where Win7 Home Premium costing around £50 or probably about $50 for the Yanks :-( :-( :-( Also, the Vista upgrade DVD allowed one to 'upgrade' onto a clean system, maybe Win7 will be similar?
This is link for MS preorder
I think apart from 100 consecutive days of support, one has to pay about £40 for support from MS even for a retail product, and forums like this one tend to offer far better tailored and faster support.

How much cheaper, do you think, will Windows 7 OEM be than Retail? On Newegg, Windows Vista Home Premium Retail is $224.99 whereas the OEM is only $99.99. Will the OEM for Win7 have such a price difference? Or do you think, since it's new, it will be like 2 bucks?

Thanks, but I'm wondering how much the OEM will be, not retail.

So I can expect it to be like $100, or so, less?