Can anybody help me with this? I am building from the command line using a batch file. Every time the batch file is run, all C files are rebuilt even if there were no changes. Building from the uVision2 IDE works as you would expect with incremental builds. I have search this site and found two memos about this. One concerns the TZ setting in the Autoexec.bat - I don't have that. The other memo states a "A=0x0" in the Defines section can cause this as well. I removed all defines and still have the problem. Any ideas? Thanks Barry