Project Summary/Abstract The National Center for CryoEM Access and Training (NCCAT), based at the New York Structural Biology Center, provides access to state-of-the-art equipment, including specimen preparation robots, high-end microscopes and direct detectors, screening microscopes, and all the other ancillary equipment required to solve structures to the highest possible resolution using cryo electron microscopy (cryoEM) methods. A highly qualified technical team provides direct support, guidance and assistance to ensure that structures of the highest quality are produced in the shortest possible time. A cross-training program provides training to users across a wide variety of skill levels and career goals. We are requesting funds to purchase fringe free illumination (FFI) and Windows10 computer upgrades for three Thermo Fisher Scientific (TFS) Titan Krios G3i instruments (Krios4, Krios5, Krios6) at the NCCAT. FFI considerably improves the throughput of data collect ion, and these upgrades will benefit all users of NCCAT. The Windows 10 upgrade increase the security of all of our systems which currently run Windows 7, which has many known security issues and is no longer officially supported as of January 2020. This means that updates to software, security fixes and technical support are no longer provided.