hi there. I've this office pc, it is an HP Compaq 7700, powered by dell invent. It used to work until the last night. I used it as usualy. Today, i moved the pc from a room to another, and when i plugged everything on and started it, it showed me a big hp invent icon, and i can choose to enter boot menu, , setup or network setup. And if i choose boot menu, it shows me a black scfeen, with the name of the pc, and thd number of ram, after one or two minutes, it shows me boot variants. Usb device, hard drive or IBA GE slot 00C8 v1240, either boot device i select, it turns a black screen for a few seconds, then the hp invent logo again, with the same opyion, i've tried again and again, but for nothing good.