Hi, I am not able to enlarge the memory size from the 256 MB default. Specifically, a perl script fails after allocating 256 MB (I get is a message "Out of memory!" when running /bin/perl.exe; in Task Manager, perl.exe had just grown its private working set to 266,xxx). I tried the following two commands, to no avail. None of the tips I found on the FAQ or mailing lists (=basically these two) worked. % regtool -i set /HKLM/Software/Cygwin/heap_chunk_in_mb 2000 % regtool -v list /HKLM/Software/Cygwin Installations\ () Program Options\ () setup\ (Cygwin) heap_chunk_in_mb (REG_DWORD) = 0x000007d0 (2000) % peflags --cygwin-heap=2000 /bin/perl.exe % peflags --cygwin-heap /bin/perl.exe /bin/perl.exe: initial Cygwin heap size: 2000 (0x7d0) MB For the reg entry, I also tried HKCU; and I closed the terminal (rxvt) and checked Task Manager that I don't I see any other Cygwin tool running, assuming this will get the DLL unloaded. I am running on a x64 Windows Server 20*12*. Could that be a problem? 2012 is listed as supported in the FAQ, but maybe something changed that got missed, e.g. some WOW reg key mapping? (The reg entry does show up in regedt32 under Wow6432Node\Cygwin; I also tried to manually create it outside the Wow node.) I am member of the local admin group. Thanks, and many many thanks to you guys for doing Cygwin! Frank --- cygcheck output attached systeminfo: Host Name: **** OS Name: Microsoft Windows Server 2012 Datacenter OS Version: 6.2.9200 N/A Build 9200 OS Manufacturer: Microsoft Corporation OS Configuration: Member Server OS Build Type: Multiprocessor Free Registered Owner: Windows User Registered Organization: Product ID: 00184-90000-00001-AA620 Original Install Date: 7/1/2013, 10:55:04 AM System Boot Time: 7/5/2013, 10:30:46 AM System Manufacturer: Dell Inc. System Model: Precision T7600 System Type: x64-based PC Processor(s): 2 Processor(s) Installed. [01]: Intel64 Family 6 Model 45 Stepping 7 GenuineIntel ~1600 Mhz [02]: Intel64 Family 6 Model 45 Stepping 7 GenuineIntel ~1200 Mhz BIOS Version: Dell Inc. A05, 11/8/2012 Windows Directory: C:\Windows System Directory: C:\Windows\system32 Boot Device: \Device\HarddiskVolume4 System Locale: en-us;English (United States) Input Locale: en-us;English (United States) Time Zone: (UTC+08:00) Beijing, Chongqing, Hong Kong, Urumqi Total Physical Memory: 130,998 MB Available Physical Memory: 104,033 MB Virtual Memory: Max Size: 151,478 MB Virtual Memory: Available: 123,520 MB Virtual Memory: In Use: 27,958 MB Page File Location(s): C:\pagefile.sys Domain: **** Logon Server: **** Hotfix(s): 66 Hotfix(s) Installed. [01]: KB2727528 [02]: KB2729462 ...