Sporadic Startup Problem

Once every 3 to 6 startups, XP will freeze on a blank, dark, screen after the progress bar that also says starting windows. The only way to get out is to hold the power button. Usually XP will start the next time. Maybe once out of 20 times it takes two attempts to start correctly. This is nn my 2nd HP laptop this issue has been going on for about a year. Running XP Pro with 1gb memory. This laptop is 4 years old.

Figuring it was a Windows issue, this weekend I formatted and reinstalled XP. Complete, not a repair or anything. Brand new and then all updates including SP3. Now the only thing reinstalled on the computer is OS, Office 2003, and Avast. I figured I was all set and good to go. Not.

Today the new install did the same hang on startup. Held down the power button to reset it and then chose "Normal" startup from the menu and it started OK.

So obviously it was not a 4 year old install of XP that was the issue. I am thinking it might be hardware related as the computer is so clean at this point.

Does anyone have any ideas what to look at next?

Thanks!