Over the Xmas period it would seem that someone deleted a computer account from AD. This meant that the user of that PC could not log in using that PC. This is a Windows 2008R2 forest so to restore the computer object;
Get-Adobject -filter {samaccountname -eq “pcname$”} -IncludeDeletedObjects | Restore-Adobject
The $ on the pcname is important – computer objects in AD always have $ at the end of the name as part of the samaccountname attribute.
Cloudy, with a chance of networking and IaC 