My internal HDD is 3 TB. Since MBR allows a maximum of 4 partitions I only made 3 partitions. But there is another restriction. Total disk size cannot exceed 2 TB. Using GPT gives boot problems and also said it is not a genuine windows copy. So I tried to reinstall the OS with my installation disk but windows said it cannot install itself on a GPT partition. That is why, I believe, the moment I switched from MBR to GPT, windows decided it was not a genuine version.
Fact is I have about 800 MB, unallocated in MBR, which physically exist but I can't use. How can I fix that?
Would Win10 have the same problem?
Thank you very much for any help I might receive as well as for all the other useful suggestions received in the past for other issues.