Activating fresh install on preinstalled OEM laptop

I have a laptop which came with Windows 7 Home Premium 64-bit. I did not make recovery disks or record the COA serial on the bottom. The hard drive failed, I have replaced the hard drive, and would like to install and activate the same OS that came with the laptop. I do have the Product ID and the original pre-installed (OEM) product key. I have working setup disc for Win7, correct edition and architecture - but it's retail. I have installed it successfully, but activation failed with the original OEM key.

The problem is that the COA key on the sticker on the bottom of the laptop is unreadable because the sticker has been worn out. I can read some characters of the key, however, so I have narrowed the key down to a set of 384 keys. However, it is not practical to try each of those possible keys. I think if I had the COA key, I could activate it, but there isn't really a way to get it at this point.

Is there a way to activate with the OEM key, other than what I have tried (i.e. activating from inside the completed install.) ? I think I read once that if you have the iso of the setup disc and can edit the files and repack it, then you can change it from a retail to OEM image by editing one file. Is this true? If so, I think I will try installing using that modified image. Otherwise, are there any other options?

Thanks in advance

PS: I have checked and I can purchase recovery discs from the Gateway (the OEM) but I would prefer no-cost options.

Download and run Belarc Advisor, which will display an inventory of the computer including the product keys of any installed software, including the operating system.

Belarc Advisor - Free Personal PC Audit

You should then be able to install to install Windows with this product key, providing the version you are installing is the same as the OEM operating system.

Clean Install : Factory COA Activation Key

I ran Belarc Advisor before I wiped the drive and reinstalled windows. That's how I got the OEM key that was used for the factory installation. That key is not working with the retail windows 7 that I installed, which is the same edition and architecture as the original installation. Belarc did not give me the COA key.

seavixen32 said:

Download and run Belarc Advisor, which will display an inventory of the computer including the product keys of any installed software, including the operating system.

Belarc Advisor - Free Personal PC Audit

You should then be able to install to install Windows with this product key, providing the version you are installing is the same as the OEM operating system.

Clean Install : Factory COA Activation Key

You can not use the factory OEM-SLP activation method Product Key that Belarc, may/may not find to reinstall Windows.
System Locked Preinstallation - Wikipedia, the free encyclopedia

Do you think that disc would need to be an OEM disk for the same model as my laptop, or just the same manufacturer?

fseal said:

The best I can think of is that you need to get a hold of an OEM install disk of Home Premium (or whatever version you originally had). Then your key may work. See if a friend has one or something...

factory OEM disk

That actually doesn't answer my question.

I know that I could use a set of recovery discs made by the same model of laptop, but could I use discs for any Gateway laptop? (Mine is a gateway.) I'm guessing probably not.

No, make & model in specs, therefore factory OEM disk