Well...do you have an O/S to install on it? What O/S is currently installed?
You have a valid Windows license and method of install?
For the record...did you ask just what is supposed to be wrong with this computer? It could save a lot of wasted effort.
System manufacturer and model?
For the record, you can read all about 7B STOP errors at http://aumha.org/a/stop.htm
. 7B, left column.