Windows are not working

it depends on year of manafactuer as to where the realays are might actualy be underrear passanger seat or under the bonnet sould be marked on the plastic cover

Chances are it is not a relay but a dirty switch. When the switches on these cars get dirty they will either only work sometimes or not at all. You can take apart the switches and clean them I do not recommend this unless you have experience doing this as there is a lot of small parts. Your best bet would be to pick up a few new switches and see if that resolves the issue. If it does not then you have an electrical issue. There is NO replay under the dash for the windows. The relay for the windows is located under the rear seat and is call the A-1 general module. It is a green rectangular box located, again, under the rear seat on the drivers side. If a new switch doesn't resolve the problem and new A-1 GM will