I'm pleased to announce that future Revolutions Pack 9 version will include technology which will greatly reduce USER resource usage in common scenarios. After your reports and my research i found a big hole in USER heap which i'm able to plug. Hole I found is in the design of list and combo box controls built in USER subsystem which consume a lot of space in 64K heap. The issue is so bad that any application that uses list/combo boxes makes easily noticeable impact. Less than 300 combobox windows can be created on pure system (while global windows limit should be 16000). To solve this issue, combo and list boxes had to be completely rewritten. That was hard task (on which i worked on for long time), but it's near finishing. 'Beta' version is kinda ready, but there are known compatibility problems and RP9 re-architecting tasks to be done. Test numbers: My unscientific 'Load 3 ImgBurn copies' test shows 65% USER free up from 39%. If you're interested in your scenario, i'm ready to test it.