10 Update issues

Hi, Windows.old is created after a major build upgrade- and there hasn't been one of those for a long time.
Normally it's deleted automatically after (by default) 10 days.

You've not specified your build number despite the forum prompt.

From the huge searchable Tutorial section:
How to Delete Windows.old and $Windows.~BT folders in Windows 10

Icecream Photo Editor 1.33 claims compatibility to Win 11, so would expect it to be ok.

could not download. Browser crashed.'

- doesn't sound like a problem with that particular program.
It downloaded and installed ok for me using Firefox from
Free Photo Editor for Windows - Icecream Apps

The drive on UNC share you selected does not exist or is not accessible

Possibilities:

The app may have dependencies that are not installed on your friend's computer: Some apps require specific libraries or software to be installed on the computer before they can run properly. Check the app's documentation to see if there are any prerequisites that need to be installed.

The app may have a bug or compatibility issue: The error message may be caused by a bug in the app or an incompatibility issue with your friend's operating system or hardware. Check the app's documentation or support forums to see if others have reported similar issues.

The file or folder may be corrupt or damaged: If the app is trying to access a file or folder that is corrupt or damaged, it may result in the error message. Try scanning the disk for errors or running a disk repair utility to fix any issues.

The user account may not have sufficient permissions: If your friend is running the app under a restricted user account, they may not have sufficient permissions to access certain files or folders. Try running the app as an administrator or granting the user account the necessary permissions.

The network connection may be unstable: If the app is trying to access a file or folder on a remote network location, an unstable network connection may result in the error message. Try checking the network connection or copying the file locally to see if the issue persists.

Start by running the usual set of disk checks. (3rd party e.g. Crystal Diskinfo + chkdsk & if those are ok, SFC /SCANNOW).

Open a CMD window as administrator and type:
winver
it will give the current version installed

As Dalchina noticed, a Windows.old folder is generated on a version upgrade and it has the previous version on it. With the Windows.old you can roll back to the previous installation.

Lets do the basic
Open a CMD window as administrator and type:
chkdsk c: /f
It will say your disk is in use and ask if you want to schedule to next start = yes
Restart

(if you want to see the check disk log: Read Chkdsk Log in Event Viewer in Windows 10)

Back to Windows, open a CMD window as administrator and type:
sfc /scannow

If it finds any corrupted files, fixing or not, reboot and run again

Then run
Dism /Online /Cleanup-Image /ScanHealth
and
Dism /Online /Cleanup-Image /RestoreHealth