Cannot flash Pegatron A15 bios v207 with v303 due to alleged mismatch in size and/or ID

If you don’t have a COA sticker I assume then the system was not one purchased with preinstalled Windows but windows came from another source. If they did come from some place else then you will need to make sure that what you have is valid to be used on the system you have.

As for SLIC, its not a case of opting out exactly, it is simply a choice of method by which system builders licence units. Whatever works for them and the manufacturing process they use, although you normally find all the big OEMS like Dell, HP etc will always use SLIC/MSDM as Microsoft require them to do so. We didn’t sign up for OA2.x so we didn’t use it for WIndows 7 however we did join under OA3.x so since Windows 8 we have shipped systems that use Digital Product Key and have MSDM Table to hold that information. Once again its a choice thing we could still have easily not done so and used 5x5 product key COA Stickers if we wanted.