On Windows, the EFI partition is only 100 MB. You may be able to extend it if there is free space between this partition and the next one. This may not be possible though.
Windows Updates or remnents of previous bios updates can easily clog this up, leading to problems like:
- Failed Windows updates
- Errors when updating the bios (experienced this with my ThinkPad)
From this Microsoft support article, run this in an administrative power shell to remove unneeded fonts to free up space:
# mounts the system partition so we can access its contents
mountvol y: /s
# switch to the partition
Y:
cd EFI\Microsoft\Boot
# get the folder size of the Font folder
Get-ChildItem -Path Fonts -Recurse -File | Measure-Object -Property Length -Sum
cd Fonts
# copy these fonts first to another location so that they can be restored later
del *.ttf
# feel free to browse around to see if there are other files to delete but be careful!
# If you're not sure what something is for, leave it aloneOnce done, retry whatever that failed. After a restart, the y: mount point won’t be there anymore. You’ll also want to restore the deleted fonts, either by putting the files back or following the procedure in the linked note.