6 Easy Steps to Boot ASUS Eee PC from an External Device:
I still love my old Eee PC after all these years...but I had a helluva time getting it to boot from an external drive so I could try out a certain linux distro.
Tapping the Esc key upon booting is supposed to bring up a boot menu - but no luck.
Turns out by default, it was configured to "quick boot". To change this:
1. Turn off your Eee PC.
2. Turn it back on, tap F2 immediately. This should get you into the BIOS Setup menu.
3. Scroll over to the "Boot" tab.
4. Select "Boot Settings Configuration".
5. Use the minus key to change "Quick Boot" to Disabled.
6. Press F10 to Save and Exit.
Upon rebooting, hit Esc and you will be presented with a Boot Device selection menu.
This method was tested on a 1000h, however I suspect these steps will also work for many older ASUS Eee PCs. "Quick Boot" may be listed as "Quiet Boot".