How to force a factory reset or hard reset on Archos devices

Archos 116 Neon Archos 116 Neon
Archos Core 70 3G Archos Core 70 3G
Archos Core 70 3G V2 Archos Core 70 3G V2
Archos 70d Titanium Archos 70d Titanium
Archos 40 Access 4G Archos 40 Access 4G
Archos Core 101 3G Archos Core 101 3G
Archos Core 101 3G V2 Archos Core 101 3G V2
Archos Core 57S Archos Core 57S
Archos Core 55S Archos Core 55S
Archos Core 60S Archos Core 60S
Archos Junior Phone Archos Junior Phone
Archos Junior Tab Archos Junior Tab
Archos Access 57 Archos Access 57
Archos Oxygen 101 4G Archos Oxygen 101 4G
Archos 101f Neon Archos 101f Neon
Archos Core 55S Ultra Archos Core 55S Ultra
Archos Oxygen 101 S Archos Oxygen 101 S
Archos Access 50 S Archos Access 50 S
Archos Core 62S Archos Core 62S
Archos Diamond Archos Diamond