How to restore Ubuntu to a previous version?
2136
How to roll back Ubuntu to a previous version?
28535
How I do a system restore?
59088
How to upgrade to a newer release of Ubuntu using the Live CD?
64186
How can re-use Ubuntu which was installed via Wubi on Windows 7?
19087
How do I recreate a deleted '/var/lib/dpkg' directory?
42634
How do I upgrade to the development release (aka. Ubuntu+1)?
20399
How do I upgrade from 14.04 LTS to 16.04.1 LTS?
36703
How do I upgrade from 12.10 to 13.04?
148973
How to restore Windows boot loader after removing Ubuntu
122007
Dual boot. How do I reinstall the Ubuntu partition?
128471
How do I update from 9.0.10 to 9.1.0?
846
How to reinstall Ubuntu keeping my data intact?
125976
What Happens When I Upgrade Ubuntu?
63176
How can I update to Ubuntu 21.04?
94125
Accidently deleted /usr/lib, how do I restore it?
3776
How to restore a system after accidentally removing all kernels?
17812
Restore database from backup file of different version / edition