Does updating iOS to 7.0.4 delete all installed apps?
AI agree with Jan. The upgrade should not touch your data or apps. That said, you should back up your iPhone/iPad before upgrading in case something goes wrong in the process.
Updating on the device itself from e.g. 7.x to 7.0.4 (if available) doesn't delete anything. The device will just restart and be done.
Updating within iTunes will create a backup, factory restore to iOS 7.0.4 and then restore the backup.
iTunes backups only contain user settings and data, but only a list of the Apps and media present on the iOS device.
If all the Apps and media is present within the iTunes Library they will be restored too.
Any Apps or media not present within iTunes won't. The Apps will have to be downloaded again, same goes for media purchased via the iTunes store.
If you are using iCloud backups all the settings and data will be restored from the backup, Apps and media will be re-downloaded from the App store automatically.
Thanks. Please tell does upgradation reset the mobile internet settings?
Manual APN settings should be retained and/or restored from the backup during an update.