Yes, it's normal to have 8.1 system files occupy 32GB and there is not much you can do. You'll need to use external media, or online storage for personal files.
SD card slot might be nice option.
WinSxS is NOT the culprit, it's been discussed much. In short, nearly all system files that comprises the Windows OS since Vista are hardlinked against content of WinSxS folder, i.e. Component Store. So actually, even if WinSxS folder shows to be of huge size in windows Explorer and other softwares as WinDirStat, the folder doesn't occupy nearly any space exclusively. And if you delete something from it, you won't get expected free space back.
Any attempt to delete, or move these files will most probably break the Windows Update system, or more. There is a WinSxS cleanup task scheduled to run monthly, you can run it on demand and gain some space sooner. There are folders worth checking inside the WinSxS, see below.
Although there is no permanent solution to reclaim free space from OS, you may gain some by deleting temp files and by moving some to external media.
These folders contain files which could be removed without damage to the Windows, but many of which are either deleted by OS maintenance task automatically in time, or would be re-created again soon after deletion. But there might also be some orphaned files and files which are there just in-case and could be deleted. Search especially for files/folders older than one month.
Windows Update
\Windows\SoftwareDistribution\Download
do "net stop wuauserv" before
Baseline Patch Cache
\Windows\Installer\$PatchCache$
for downgrading, patch uninstalling, but updating will still work after deletion of this folder
Blob files inside WinSxS folder
\Windows\WinSxS\ManifestCache*_blobs.bin
Blob files are used by MS Update and are normally deleted after one month.
temp folders inside WinSxS
\Windows\WinSxS\Installtemp
\Windows\WinSxS\temp
Don't just delete these. If they grow huge, check how to purge them properly.
Inside are most likely just hardlinks and deleting those won't solve nothing, but on the contrary might leave their hardlinked copies being stuck someplace else.
Temp and Logs
\Windows\Temp
\Windows\Logs
%temp%
Installer folder (to be moved)
\Windows\Installer
This folder holds Microsoft Installation MSI files and last patches, MSP files, for products installed by MS Installer. If you remove them, you'll not be able to Update or Uninstall these products, but you can move those bigger ones to external media, and when Windows or you will try to update a product which would require one of them, it would show error dialog and you can then move the required MSI/MSP file back and repeat the update.
Cleaning some of these folders and also to manually run Component Store clean-up could also be achieved by Disk Cleanup in win 8.1
It's worth checking if you don't have recovery partition on this drive, and if yes, moving it to external media, reclaiming space on drive. Run command "recoverydrive"
secondly, if your OS was pre-installed, it happens that manufacturer would reserve more space that necessary for system partitions.
It was so in my case.(lenovo)
check it using diskpart: select disk 0, list partition
for UEFI system, Recovery 300MB (mine was 1000MB), System 100MB (mine 260)
for BIOS system, Recovery 350MB, and there is no System partition
If your system/recovery partitions are excessively large, use 3rd party partition manager program to shrink them.
