My iPhone 4s has gotten stuck in 'Reset and Erase All' mode for hours

If you prefer to have a flowchart to narrow down the cause of why an iOS device won't restore, try this assistant:

• http://www.apple.com/support/iphone/assistant/restore/

If you prefer to have a list of steps, this article should help:

• http://support.apple.com/kb/HT1808

Sadly, there are many, many reasons why restores fail, some are antivirus software being too protective, some are computer problems, some are hardware problems and others are missing drivers or just bad timing.

Once you narrow down which exact step fails in the lists above, you can ask a new question if you continue to have issues restoring your iPhone. More than 30 minutes usually means there is a problem that will prevent a good restore from finishing.

Have your iPhone been jailbroken? You cannot hit "erase all contents and settings" when jailbroken. Ever. It will break things, and this will happen.

If you must use iCloud, then you have to restore to 6.1, then restore from iCloud, then run evasi0n. Or, just use iTunes to restore from backup (after you know, making a backup).