How to switch from Lucid 32 Bit to Lucid 64 Bit

[SolitaryMan1941]

I recently upgraded from Karmic to Lucid via the Update Manager. I would like to upgrade further by switching from 32 Bit to 64 Bit. I downloaded the Lucid 64 Bit ISO and wrote an install disk. When I reboot the computer with the install disk nothing happens. Any ideas?

[wil08son]

Your computer may look to boot from the hard drive before the CD/DVD drive. When your computer initially starts up, something like "F12: Boot Menu" should flash on the screen. Hit whichever function key you need to and then choose to boot from the computer's CD/DVD drive.

[SolitaryMan1941]

I wrote another install disk at a slower speed and everything went smoothly.

Thanks!