diff --git a/modules/ec2/windows/locals.tf b/modules/ec2/windows/locals.tf
index cefa024..f552a2c 100644
--- a/modules/ec2/windows/locals.tf
+++ b/modules/ec2/windows/locals.tf
@@ -12,12 +12,14 @@ locals {
 
   # VPC and networking - only resolve if vpc_name is provided
   vpc_id = var.vpc_name != "" ? data.aws_vpc.vpc[0].id : null
-  az_name = var.vpc_name != "" && var.subnets_name != "" && length(data.aws_subnets.subnets[0].ids) > 0 ? data.aws_subnet.subnets[sort(data.aws_subnets.subnets[0].ids)[0]].availability_zone : null
+  selected_subnet_id = var.vpc_name != "" && var.subnets_name != "" && length(data.aws_subnets.subnets[0].ids) > 0 ? sort(data.aws_subnets.subnets[0].ids)[0] : null
+  az_name            = local.selected_subnet_id != null ? data.aws_subnet.subnets[local.selected_subnet_id].availability_zone : null
 
   # Add networking parameters if available
   network_parameters = local.vpc_id != null ? {
-    VpcId  = local.vpc_id
-    SubnetId = data.aws_subnets.subnets[0].ids != null && length(data.aws_subnets.subnets[0].ids) > 0 ? data.aws_subnets.subnets[0].ids[0] : null
+    VpcId    = local.vpc_id
+    SubnetId = local.selected_subnet_id
+    AZName   = local.az_name
   } : {}
 
   parameters = merge(