Gberk on "Update 3.5.1 keeps failing on IIS7.5"

I cannot update 3.5 to 3.5.1.

Server: IIS7.5

Tried the Codex tips:
1. Hotfix plugin: does not help
2. tmp folfder via wp-config: does not help

This is frustrating, never had any issues updating WP. Who can help?