Windows 7: Will a factory OEM key work with a retail re-installation?

I am helping a friend deal with his malware infested PC. He already took it to a Famous Electronic Store (the Best place to Buy stuff) and asked the geeks to fix it. One week and two hundred dollars later, it is still infected with the same scareware and hijacker... so now it's up to me. Yikes!

I am leaning toward pulling his personal files, wiping it, and re-installing the OS. He has only the usual factory recovery disc.

I would like to use my retail x64 disc to install the OS, and put in his product key when activating it. Will that work?

Not sure....if its the same OS and bit I would think so. I've never tried it. What does it look like in disk management? IS the hidden OS partition still there and does it say healthy partition. Depending on make, there are options to reset to factory condition....whether with built in proprietary software or from the hidden partition.

Well, I think the hidden OS partition is still there... the first partition on the HD is labeled "OEM partition"; at 64 MB it's about the right size.

But I don't know if I want to trust that it's clean and disease free. This PC has been infected since November when he took it to the geeks, and has resisted every fix thrown at it. I think I might be better off if I start completely clean...

The hidden partition is generally 8 to 12 gigs for the factory OS...not in MB. Now there is a 100 mb partition and contains important bootable files. See post here for that info...

What's on that 100MB partition? Can I delete it?



I don't have a hidden partition because this is a custom build and I have the disk to re-install.

This PC has one HD with three partitions:

The first is 64MB and is called "OEM Partition"; Simple, Basic, *no file system*, Healthy (OEM Partition)
The second is "Recovery"; Simple, Basic, NTFS, Healthy (System, Active, Primary Partition)
The third is C:; Simple, Basic, NTFS, Healthy (Boot, Page File, Crash Dump, Primary Partition)

But I don't really think any of this matters... I don't want to try any recovery/restore function. I think that's what the geek squad guys did, and it didn't work. Heck, for all I know, the scareware/hijacker could be hiding out in the OEM or Recovery partition.

What I need to know is whether a Dell OEM supplied key will work with a retail installation... I don't know if MS has some way of differentiating the two. Or if they even care to differentiate.

You can use any installation disc and apply the key that is on the PC's COA sticker (not the one that you see in Computer Properties that has 'OEM' in the middle). But you must have the same distro - e.g. Home Premium 64bit. The key for that would not work on a Home Premium 32bit or a Professional 64bit.

Thanks whs. That's what I figured, but I wanted to be sure before I brought out the blow torches and cattle prods. (heh)

Now I just have to figure out which product key is the correct one -- the sticker says one thing, and jelly bean says something else. I wonder what those geeks did to this thing..?

I've been waiting for someone to mention the procedure to modify the installation to make it generic, by removal of the ei.cfg file.

Does that extend to OEM keys? I vaguely recall reading that it does, but I've never tried it myself.

The geeks have probably stolen the product key and installed some pirated key that will expire all of a sudden. If that is the case, you have a problem and might have to call Microsoft. In any case, it is the key on the COA sticker that counts.

Another possibility is that the system was upgraded at a later time and Jelly Bean shows the upgrade key. Ask your friend.

Clean Reinstall Factory OEM steps