I recently started a pilot for a migration from Windows NT4/MF1.8 to Windows 2003 server/MFXP FR3. I went from 4 proc HP DL580s (mostly) to HP BL20P blades (150 in all). The main application is a home made powerbuilder 9.0 based application to run our billing system. The issue I am seeing is that on the 2003 servers, the application is using significantly more memory than it did on NT4. For example, one of the subsystems ran at about 1-3MB on NT4. On 2003, it is a consistent 19MB per user. Other subsystems that ran at 15-30MB on NT4, now run at 25-50MB. Another weird issue I am seeing is - When you launch the main application window, you can choose different subsystems to launch. When you launch a subsystem, the main application window is minimized by the application. On NT4, when the main application window is minimized by the application, most of the memory is released. On 2003, when that same window is minimized by the application, the memory stays the same - nothing is released. If you click on the minimized application on the start bar, and minimize it again (manually - by using the windows minimize button), the memory is then released. My question is: Has anyone seen such an increase in memory utilization going from NT4 to server 2003? I thought server 2003 would manage the memory better than NT4. Any suggestions on memory hacks for 2003 server? I have tried running other (non homegrown) applications on both servers and compared the memory utilization. The 2003 server seems to always use more memory than the NT4 server. Server info: HP bl20p server blades 2 Proc 2.8GHz 2.5GB RAM Anthony Rallo Systems Engineer 773-399-7552 tony.rallo@xxxxxxxxxxxxxx <mailto:tony.rallo@xxxxxxxxxxxxxx> US Cellular Bensenville Office