Computers usually throw that error when the system bios can't find an operating system to boot to. 99% of the time this indicates a failed hard drive. Take it to a professional and have them remove the hard drive and try to recover your data. You can also get into the bios and see if the system is seeing the hard drive. When the Compaq splash screen comes up you'll have to press a key to get into the bios (it usually says press F2 to enter setup) but it could be any number of different keys to get in, every manufacture is different. It'll either be esc, del, F2, F10 or F12. Once your in the bios poke around in the menus and see if you can find the section that contains the hard drive settings. (It's usually the first screen it opens to) But seriously, if you don't know what you're doing I wouldn't recommend trying to fix it if you have important data you need.
More than likely when you pulled that plug it fried your hard drive........sorry
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