any help please?
my friend brought his car over to my house to change the head unit,we had to go out to get something from the shop,and now the key doesn't turn in the ignition?

it's a spare master key,which isn't programmed to the car yet
any idea's? it's also blocking in 3 other cars,mine included,so help please

You might want to post this in the GS section if this is regarding a GS ? (going by your profile info).

Whether the key turns in the ignition or not is about if it's been cut correctly as a key that will operate the ignition lock, as well as if the lock is working mechanically or not (e.g. they can break on the IS200).

Has this spare key ever turned in the ignition ok ? Do other keys turn in the ignition ok and just not this one ?

Are you saying you've tried these keys in other cars ? I'm confused as to why you're trying that because a key for one car is never going to turn the ignition of another car.

got it working now,looked up some old threads and found the answer,which includes a hammer
sorry no shoudl have said it's my friends IS200,which was blocking my GS300 on my driveway.
from looking at previous threads it appears he will need a new ignition barrel,yes his old key which he lost turned fine,and so does this one,he put my GS key into his IS by mistake at first,think that might have jammed it up,but all sorted now thanks anyway for the reply

ok, a spray of WD40 might free it up temporarily, but it might still break completely at some point (or might have done so already), so worth checking out a new one.