Hi, I'm currently using a Lenovo Y510P laptop, which I bought with an OEM installed, but I've removed it and clean installed Windows 10 with a recovery media I made with Microsoft's tool Anyways.. in the process, I've noticed my laptop has a lot of, probably some unneccesary partitions left by the OEM. Some were named "OEM Reserved" or Recovery Drive. I've deleted some but I don't seem to be able to merge these with the Primary, C: drive I have windows installed in. As you can see, I've deleted the partitions, but I don't seem to be able to combine it with the main one as the "Extend Volume" option is greyed out. So, here were my questions. 1. I'd like to just combine them all and then keep them as two 500 GB partitions. How can I combine these? 2. What is the EFI System Partition? It seems important so I just left it, but I'm willing to do another clean install if its needed to get this organized. Can I also delete the EFI system partition and combine them all if I'm planning to install window cleanly?? Thank you.