I recently bought Pathfinder:Kingmaker and while it seems to run fine I keep getting an update error telling me I'm out of disc space. I have 21 Gb of free space on my C: drive according to Windows.
Can anyone explain to me what that's all about?
Cheers,
Tony

Is this just a pop-up that appears randomly, but everything seems to work normally? Are you using Windows 10? If you go to the "This PC" window, do you see a hard-disk partition, with almost no free space, that shouldn't be there?

I had this problem for a while, and apparently it's just a side effect of a recent Windows 10 update (number 1803). If that's the case you're not really running out of space, but the update turned one partition (reserved for system recovery) visible, while it should be hidden. I used these instructions to hide it again: https://answers.microsoft.com/en-us/windows/forum/windows_10-update/update-1803local-disk-e-running-out-of-space/7223a24c-51ae-40a4-ad5b-5628b394dd9d

21 gigabits is REALLY LITTLE in this day. 21gigabytes is a bit more, eight times more to be exact, but still less than comfortable for Windows.

Press Start button and type Disk Clean-up. See if you can free up some more space. If you only have 21 GB left, it's probably time to start thinking about adding an extra hard disk or SSD. I don't know if you have a desktop or laptop, your post is a bit light on details.

Getting that OS message was pretty common,less so nowadays.Some games had a nasty bug that used that one:)

I think the last time I saw it was before I bought that "huge" 80GB HD.

Thanks for the feedback chaps.
My drive actually has 118Gb. The 21Gb is the current free space.
@Caesar - I can't see a partitioned section, but I think You're right that it's a Windows 10 artefact. The game seems to run just fine.
@teceem - I would if I wasn't such a hardware doofus and not actually know how to go about it :D

21gb free space is tiny nowadays. I would highly advise a good cleanup, uninstall things you don't need etc. Even if you can still run things, temporary windows downloads, caches, game saves etc. Can quickly swallow 21gb, heck most recent releases big games are bigger than that now.
As a rule of thumb, if I hit 50% capacity, then I have too many things installed, most of which I likely don't use.

You can find plenty of videos on Youtube on how to do it. ;-)

I know right? To think, that my first computer had only 1GB of total disk space(for Windows and games).
My second computer had 40 GB, and again it wasn't enough for the times.
My third had 80GB + 160GB, and that soon after, proved insufficient.
My current computer has 512CB SSD + 2TB HDD + 10TB external drives. And I'm kinda comfortable with that, but games are getting ridiculous. With the advent of un-compressed textures, they are going over 100GB.

Aha. Think I've cracked it. What I didn't realise was that GoG installs to the c:users area by default. I was able to disabuse it of this notion, uninstall and reinstall on the D: area where there is MUCH more room. Problem solved... at least for now :D
Thanks all.

My first pc probably had only some MBs in total XD

You just graduated from Doofus to N00b! ; )

Glad you got it sorted.