Which is better: Full Scan in Safe Mode, or Scan with Norton Bootable Recovery Tool?

What's the difference between scan my computer

 

on safe mode and or with norton bootable recovery tool?

 

which's better thank you.

 

Because i tried to scan my pc with norton bootable recovery tool , but the virus definitions isn't update I have DSL and permanent connection.

 

Thank you to all and I hope can help me.

 

[edit: changed subject to better reflect thread topic]

Generally speaking, you should be running your scans in normal mode.  Safe mode is only used when you can't use normal mode for some reason, or if the malware needs to be inactive to be removed.  The bootable tool is for recovery when you can't reliably get into your system due to infection.