error in rebuild

i hv installed "Keil uVision4", i hv created the project, new file, added that file to source group, wrote a simple code all done successfully. Now when m rebuilding the target, its showing an error "--- Error: failed to execute 'C:\Keil\C51\BIN\A51.EXE' ", saying that target is not created,

Pls tell me if m proceeding correctly or not. if yes, then what to do next.

thank U !!

 d you delete it or move things around?

if you did a standard installation and did not delete it or move things (Keil stuff, not your source) around it should be there. if not, just copy it from the install (or just reinstall)