battery drain ??????

its a cold winter and i left the lights on 1 night and the battery was dead the next day. had the road service out and the guy said the battery looked new and said all i needed was a jump and to run the car for 2 hours and then trickle charge it overnight. since that night the windows only go up an inch at a time or at all. i thought it might be the switch but its all the windows that do it. ths SRS indicator light is on now also. the wife says she has had problems with the key fob opening the doors but since the battery charge she's not having it. 1999 320 e just bought off a little old lady with only 27,000 miles on it. i'm starting to wonder why she sold it??? need help, do i need a new battery ???