Hi, I still have the problem to use the PBP under MPLAB. As suggested I have update the autoexec.bat with the corresponding path. But after adding at the DOS path for the PBP and the MPLAB, and restarting the WIN 98, the building problem remain the same as: --------------- Building LEDBLINK.HEX... Compiling LEDBLINK.BAS: Command line: "C:\PIC\PBP\PBPW.EXE -ampasm -oq -p16F84 C:\PIC\PICPRG\LEDBLINK.PBP\LEDBLINK.BAS" MPLAB is unable to find output file "LEDBLINK.HEX". Build failed. -------------- the content of the "PROJECT WINDOWS" is: ---------------------------- Project Listing Path: C:\PIC\PICPRG\LEDBLINK.PBP\ Project Name: LEDBLINK.PJT Target: LEDBLINK.HEX Tool Suite: microEngineering Labs, Inc. Processor: PIC16F84 Development Mode: Simulator Target Data File List: LEDBLINK.BAS; Option String: -ampasm -oq; Build Tool: PicBasic Pro Compiler Node: LEDBLINK.BAS ---------------------------------- and my path is: PATH c:\;c:\nc;c:\sviluppo\qb45;c:\pic;c:\pic\pbp;C:\BITWARE;c:\programmi\mplab; the PBP is installed in c:\pic\pbp and the MPLAB is installed in c:\programmi\mplab As a test of the correct working of the path, i have launched the pbp.exe and the mplab.exe staying into the \windows directory and the two program are reached and started correctly. Sameone have been the same problem?? And have been solved?? Anyone have suggestions?? Thanks at all. Leonardo