I use mplab 3.1 and assemble with its mpasm 2.01. Instead of launching mplab I wanted to simply assemble some code by launching mpasmwin.exe only, without the mplab shell. I select the code (which assembles fine under the mplab shell) in the mpasm window (as I used to do before using mplab) and select the options but when I click assemble I immediately get 'Dos error: file not found' - it does not say what file has not been found. The previous mpasmwin.exe used to work fine on its own. I have not got any include files, just the one simple bit of code. If anyone knows what the file is (it nothing to do with source) which mpasmwin says is missing then please let me know as there is nothing in the help files about this error message. Thanks steve@s.ssystems.easynet.co.uk - http://easyweb.easynet.co.uk/~s.ssystems Stephen H Alsop, S&S Systems Ltd, UK. Tel: 01909 773399, Fax: 01909 773645