I am just guessing this is the BIOS Logo that comes up before windows starts.
If this takes a long time, it is usually due to a missing or faulty component. (like a hard drive or other device that is enabled in the BIOS but does not exist. Go into the BIOS and check the settings, also disconnect any external device except keyboard mouse and monitor (printers especially could cause this).
I know this is vague, but I'd be looking at many things like this, hope it helps
Astrophel at capitaltechmd.com, February 2009