thank you! thank you! thank you!
you have saved my skin!
it works and is on its way to bring joy to the masses ;)
i reinstalled but this time checked the cleared settings box as you suggested. it did the trick. i have opened and closed hoster twice, rebooted twice and it still works. so a million thank you's for that suggestion.
i have never had to check the clear settings box before but i will keep in mind if similar situation occurs in the future.
it is very good to know that there is no auto disable feature. i went with the upgrade because i had a limited amount of time to try everything i could think of.
yes, vista could be the issue. 2 run vista and 3 run win7 (or the other way around)

it has never been an issue until today.
as mentioned. i had not made any changes since it ran last night but, when it comes back after the show tonight i will double check if the os has in fact changed and will restore to previous condition if necessary.
i'll also make arrangement to get at least 4 of the systems on the same upgrade schedule in the very near future.
thanks again!