if its fat32 it should be fine...I don't remember exactly but i think exFAT option was added only in Win7...

Try formatting using vista if you are comfortable in it and transfer 1-3 files to your device first and see if they get detected...

If you get the error "Cant access user data" on your device, this means it didn't format to FAT32...Then you can use Linux with GParted to do the job for you...

If you have your data all backed-up to your PC even if you format it to XYZ format, you can do a emmc only flash to fix it in the worst case scenario so don't fret