7 - kernel - HDD timeout
16 - dashboard - Other files to do with dashboard / dashboard settings (specific dashboard error)
Smartxx.com has all the information you need, you just need to find out your Xbox version..http://www.xbox-scene.com/versions_1.php
Get your bios files from #Xbins http://www.xbox-scene.com/articles/xbins.php
(not other places they may contain PC viruse's)
And get Slayers from http://slayer.xbox-scene.com
(again only use there IRC)...
Use the latest X2 bios (I believe 5035 or 5037 or something) but only use the 1.6 variant on 1.6/B Xbox's..(X3 bios is only for X3 chip, Evox M7/M8 bios is based of MS kernel, if you use that only use M8 on a 1.6 box)..
Slayers can rebuild your hard drive, including the MS dashboard, but some of the apps maybe out of date so use #xbins to download the latest apps.
You have to unlock your hard drive and lock it on the new hard drive if you plan to upgrade your drive, if you go past 137GB you need to use the LBA48 hacked bioses.. (for all to F or F then rest to G drive), you might as well upgrade your drive for Xbox Media Centre if you can it's such an awesome app..