New
#11
To answer your question, no, you will not need any drivers for XP Mode. When you download and install XP Mode it contains a complete virtual machine with all drivers and a valid, licensed copy of XP.
As others have said, it would be best if the user moved on and went to a newer mail client since there are alternatives that are more secure and can be run directly from Win 7.
Personally, I would choose XP Mode over dual boot since, with XP Mode, Outlook Express could be installed and then accessed directly from the Win 7 desktop, whereas with dual boot, when the user wanted to send/receive mail he would need to reboot the machine.
In order to even install XP on that machine for dual boot, you will need to obtain the proper SATA drivers (XP doesn't support SATA drives right out of the box and will get a BSOD during install) and either slipstream them into the install CD per the link provided by GregRocker or have them on a floppy disk ready to be installed during install. I'm 99% sure that laptop doesn't have a floppy drive, however an external could be used. XP install is very specific and will ONLY accept the drivers from floppy and will NOT look for them on a CD (unless slipstreamed), thumb drive or any other storage device.