Sites like forums or DSLReports often have pinned threads with last-known-good (LKG) official firmware. Be cautious: only download files with a .bin or .img extension that match your region (e.g., ANZ, EU, RU).
However, if you are reading this article, you likely own a specific revision of this device: the . You may have discovered that not all DSL-2750U units are created equal, and finding the correct firmware for the D-Link DSL-2750U H/W C1 can be a confusing, frustrating process. firmware d-link dsl-2750u h w c1