Thanks Julian — this screenshot is exactly what we needed.
What your Outlook is using right now
In
Outlook → Account Settings → Data Files, I can see only these two data files:
1)
ggini@ngi.it – Outlook Test.ost
C:\Users\ggini\AppData\Local\Microsoft\Outlook\... .ost

Keep it. (OST is a cache file for IMAP; Outlook needs it. Don’t move it.)
2)
ggini1@tin.it – Outlook GG.pst
C:\Outlook Files Backup From OneDrive\...Outlook GG.pst

Keep it. (This is your POP mail storage—your real email history.)
Importantly:
there is NO “Outlook Test.pst” listed anymore, so Outlook is
not using that file.
What is safe to delete in C:\Outlook Files to save space
From your earlier folder photo, you had these files:
Safe to delete (after Outlook is closed)
[email]ggini1@tin.it[/email] - Outlook GG.bak (the big ~7.48 GB file)
This is just a backup created by the ScanPST repair.
If Outlook is working now, this is the main space hog you can delete.
[email]ggini1@tin.it[/email] - Outlook GG.log (small)
Safe to delete.
Giuliano [email]ggini1@tin.it[/email] - Outlook Test.pst (small ~58 MB)
Since it is not listed in Data Files anymore, it’s safe to delete if you want.
Do NOT delete
[email]ggini1@tin.it[/email] - Outlook GG.pst (your POP mail)
- Any .ost file in the AppData Outlook folder
Tip (extra safe): If you’re nervous, you can keep the
.bak for a couple of days; but if disk space is tight, deleting it now is normally fine (especially since you do image backups).
Optional tidy-up (not required)
Right now your PST is stored in:
C:\Outlook Files Backup From OneDrive\...Outlook GG.pst
That’s OK, but if you want it cleaner you can move the PST to:
C:\Outlook Files\
If you do, Outlook may ask you to “locate” the PST once; you just browse to the new location.
WebView2 Runtime
Yes, you
should install
Microsoft Edge WebView2 Runtime (it helps Outlook sign-in screens). The Microsoft page you showed earlier on
developer.microsoft.com is the correct official place—choose the
WebView2 Runtime / Evergreen Standalone Installer (x64).
If you want, tell me what you see on the download page (a screenshot of the download choices) and I’ll point to the exact button to click.
If you delete the
GG.bak file, how much free space do you get back on C:?