I have a Dell 1525 and for the past few weeks it has been starting up by itself. I use wireless internet. I checked the BIOS and don't see anything relating to an auto start up. I also checked to ensure my 'Wake on LAN' setting was off and unplugged my wireless modem for the day and came home to it still being turned on. I have run various virus checks (Latest Norton trial version and internet provider (Bell)) and neither has found any viruses.

Not really sure where else to check. Very random times to. Sometimes when I wake up it is on and other times it turns on during the day.

Any help would be appreciated!

I have heard or complaints about it randomly shutting off, but never about it powering itself on! Lol.. Is your virus software a legit copy and up to date?

Yes, I recently downloaded a trial version of Norton 2009.

Check all your Power Options in control panel and go through each setting to make sure laptop is being turned Off and not set to hibernate or sleep

Try to run the diagnostic or hard drive diagnostic by pressing on F12 multiple times after turning on. Don't stop tapping F12 if there's no option on the screen. Once the options are there look for the word diagnostic or hard drive diagnostic. Run the test if pass then reinstall windows. (OS)

Lol one of my customers had this problem with the same model.

Turn your computer on, on the dell logo screen push F2 to get into the bios. Go to "Power Management" and set it to Off. This customer of mine thought she had a ghost at her house because her laptop was on every morning when she woke up. Somehow it was set to turn on at midnight every night. Anyway I hope that helps :)

Sorry Power Management --> "Auto On Mode". If you want it to come on at a specific time though, just go down one more to "Auto On Time" and set a time.