Hi,
I am working on a Dell Inspiron 5000e that shuts off at different intervals. With the battery in and notebook plugged in, it will run for various lengths of times and shut down. If I remove the battery it will run overnight. If I leave the battery in and remove the HDD and boot it will go to the DOS prompt saying no operating system found and not shut down. If I unplug the power cord and try to boot I get the cursor blinking on the screen and hear a whistle type sound 3-4 times and it shuts off without ever booting to exp. The system was upgraded to XP Pro. I have gone into BIOS and stopped any settings that would power down or hibernate.