Our company has updated all computers to 21h1 and all computers that were formatted by hardlink with backup have been experiencing issues of slow explorer.exe (Desktop), extremely slow firefox (other browsers not affected) and other Microsoft programs too are slow. We've already done cleanmgr, cache, cleanup, sfc and dism, (starting third-part programs is not allowed GPO) and we only use SSDs. Most updated drivers have already been included in the image. What else can we try? The only solution we found was to delete the user and create again. We need a less drastic solution.