Cause: Permission issue or background antivirus.
Solution:
Samsung’s printer division was sold to HP in 2017. Consequently, official Samsung printer support pages have been migrated. You will no longer find Samsung-branded support sites. smarthru 4 samsung scx-4521f software download
Older URLs like samsung.com/us/support/downloads may redirect to HP. However, if you need an older version for Windows XP or Vista, archived versions exist via the Wayback Machine, but we strongly advise using HP’s current distribution for security patches. Cause: Permission issue or background antivirus
Warning: Avoid third-party websites like “driver-driver.com,” “download.cnet.com,” or “softonic.com.” These sites often bundle adware, browser hijackers, or outdated drivers that can crash your system. Warning: Avoid third-party websites like “driver-driver
Since HP acquired Samsung’s printing business, the official location for the software package is the HP Customer Support – Software and Driver Downloads page.
Step-by-step via HP: