If the disks don't say 'For installation only on a new PC' then they are retail. If that wording (or similar) is present, then it's OEM
The Product ID from teh install will also tell you - if the second group of characters is -OEM- then (obviously) it's OEM, otherwise, it's 'something else'
If there's a COA Sticker attached to the case of the machine, then the license is OEM.
If you want a more detailed appraisal....
To properly analyse and solve problems with Activation and Validation, we need to see a full copy of the report produced by the MGADiag tool
(download and save to desktop - http://go.microsoft.com/fwlink/?linkid=52012 )
Once saved, run the tool.
Click on the Continue button, which will produce the report.
To copy the report to your response, click on the Copy button in the tool (ignore any error messages at this point), and then paste (using either r-click/Paste, or Ctrl+V ) into your response.
- **in your own thread**, please
Please also state the Version and Edition of Windows quoted on your COA sticker (if you have one) on the case of your machine (or inside the battery compartment), but do NOT quote the Key on the sticker! How to Tell