All in One Bootable CD covering all maintenance purposes, most importantly rescue disc purposes.
Ranked in these QuestionsQuestion Ranking
Pro Completely free
Hiren's boot CD is completely free, always has been and always will be.
Pro Extremely popular
Hiren's Boot CD is very popular. Anyone who has ever worked in support or system administration probably has used it at least once.
Because of this, it's extremely easy to find guides and tutorials on how to use it, or if a tutorial does not explain everything, chances are that you can find someone to help you with it.
Con Not cross-platform
This rescue disc is for Windows systems only.
Con Has not been updated in years
The last release was in 2012, which is quite old at this point.