this is how we cook in uk...
1) microwave (highly recommend!)
use a fork to stab in the potato for 6 times (3 times each side)
if it's a 750w microwave oven, set 4mins than turn it over, further 2 mins
if it's a 650w or 850w microwave, just slightly adjust the time.
DONE!
2)Oven
wrap the potato(s) in foil, put it (them) in the oven
->low heat (180 C) for 4 hours!
jacket potato...
one will be ready in 7 mins, another 4 hours...
which one do you prefer?