I bought a Sandisk Ultra 64gb microSD specifically because I read it was compatible with the Surface RT. My RT recognizes it when I plug it in, but will not let me format it. I have tried all three file types(NTFS FAT and extFAT) but no go with default allocation size. It says "Windows was unable to complete format" when I try. I have tried to do it under Disk management but no go - It shows it as health with 30.99 mb as aRAW file format. I am not sure what to do at this point. Any ideas?