usb not transferring files

[rodgom]

Tablet is Nextbook 7P12 ser no.YF111212402. Two things are bugging me. I cannot seem to load files via USB from the computer(Win XP) without the computer seemingly locking up. The only way I can get control is to disconnect the usb cable. Also is there a rom to root this particular model which is not rockchip but the amlogic(M3?). Also I can't get kindle to work,and the preloaded books I can read but not those I have loaded via sd card.

[rodgom]

Tablet is Nextbook 7P12 ser no.YF111212402. Two things are bugging me. I cannot seem to load files via USB from the computer(Win XP) without the computer seemingly locking up. The only way I can get control is to disconnect the usb cable. Also is there a rom to root this particular model which is not rockchip but the amlogic(M3?). Also I can't get kindle to work,and the preloaded books I can read but not those I have loaded via sd card.

Cleared all problems by factory reset which took off several apps from playstore. Also appears from reading on forum the only way to root is via 3g dongle. Correct??