I have the Presario 1240 laptop, and I really dont like it (floppy is dead, CD-Rom cant read homemade CDs, etc). Anyway, this happened to me once. I called up compaq, and after a while, I finally got connected to a tech support rep. He said you have to do a "power cycle" or something. You have to take out the battery, plug in the power adapter, and it should boot up. Then, when it gets to windows, shut down, and insert the battery again. Dont turn it back on - just let the battery charge all the way (till the charge light goes out). Then turn it back on and play away! Now if this doesnt work...first, does the light on the little box (like it has a AC plug comming out one side and the little DC plug on the other), is the light lit up? If it isn't, then u might need a new power adapter. Otherwise, I dont know!