Originally Posted by helms1963
Can you go into setup and set date back a month or so when it was working ?
Yes you can, look for the time and date settings and follow the directions to change the time and date correctly.
I think its page up and down keys to change, havent touched a dell 2400 for awhile.
Save your settings and be sure to reboot.
if the changes were not saved and storing correctly, follow through with joes comment about the cmos battery problem.
Go back to best buy, take your cmos battery with you, tell them you need a replacement.
They should be able to get one if they have it in stock.
Also if your computer persists to shut down after 2 or 3 minutes of booting up.
Do what wilson suggested and get your cpu grease reapplied or risk over heating damages.