Check your path. I use a DOS batch file to do all my editing (Programmer's Notebook) and compiling, without the IDE. An example:

path c:\program files\pbp3;c:\program files\microchip\mpasm suite;c:\Program Files\Programmer's Notepad
REM Enter the file name, project file folder name, and PIC type. Use quotes if any spaces.
set filename=USERV200
set projectdrive=g:
set projectfile="My Job\software\New Rev"
set pic=18F67K90

REM The following stuff doesn't change
%projectdrive%
cd \%projectfile%
pn %filename%.bas
del %filename%.er
del %filename%.err
pbpx -ampasmwin -p%pic% -e -n %filename%