Try 'Safe' booting by holding down shift after the chime. You should see a grey progress bar on boot and you can release shift. This will clear caches and may address your problem.
Set up a new user account in System Preferences and config Mail in that account. If it works there you probably have a problem in your Mail preferences in the original account. If it doesn't work, Mail may be hosed and need to be reinstalled.
For ease of moving back and forth between accounts...
Chances are fair that your Airport Express may be toast. As I recall they have power supply problems particularly in some early French built models. Seems like some of those had an average life of around 18 months before failure.
If you want to tinker, futz and create problems for yourself, Microsoft makes just the operating system you seem to want. On a Mac, use the Migration Assistant and use the Ethernet option if you don't want to wait on USB. After its migrated and you're all happy in your new machine with your data...
Reload the OS from another Mac over Firewire. Boot the MBP in Target Disk mode by holding the T key down on boot and it will show up on the other machine as a disk on which to do the install.
If you have another Mac that you can connect to via firewire you should be able to boot yours in Target Disk mode by holding the t key down on boot and then run 'verify disk' against it from Disk Utility on the other machine.
Download MacTracker from mactracker.ca
Use it to find which Airport model you have and whether it will do what you want.
Here is the manual for the Airport model that will let you do wired and wireless network connections...
Boot from the Install CD that came with your machine by holding down the C key. Go thru a few screens until you get a menu bar and under Utilities you will have Disk Utility. Light it, select your drive and click repair disk. Chances are it will find (and correct) errors on the drive.
Boot it in Target Disk mode by holding the T key on boot. Hook up another Mac by Firewire and go into the Desktop Folder in your home directory and delete the jpgs.
is that easy. You'll need an Airport Card and the card carrier. Install the card in the carrier and use a coin to open the RAM access slot in the bottom of the machine. The antenna wire should be hanging on a silicone rubber tab near the RAM. Insert the antenna Firmly into the hole in the...