Hi, I downloaded the source files of FSL and successfully compiled using cygwin with gcc-2.95.3.10 under WindowsXP. And then I type "fsl" to get into the user interface. I fisrt tried BET and it excuted without any problem. Then I tried to use FAST to segment the data output by BET but nothing happened after I click "OK". I then try to use the command fast to segment the file and get the following screen: ---------------------------------------------------------------------------- -------------------------------------------------- FAST - FMRIB's Automated Segmentation Tool Version 3.3 Image: xxx_brain.hdr Segmentation fault (core dumped) ---------------------------------------------------------------------------- -------------------------------------------------- I found a fast.exe.stackdump generated automatically and the content of the file is the following: ---------------------------------------------------------------------------- -------------------------------------------------- Exception: STATUS_ACCESS_VIOLATION at eip=2CB41780 eax=FFFFFFFF ebx=0A041B14 ecx=00000000 edx=00000000 esi=0A0419B0 edi=0000015C ebp=4088B490 esp=0022CF38 program=C:\cygwin\usr\local\fsl\bin\fast.exe cs=001B ds=0023 es=0023 fs=003B gs=0000 ss=0023 Stack trace: Frame Function Args 3 [main] fast 3640 handle_exceptions: Error while dumping state (probably corrupted stack) ---------------------------------------------------------------------------- -------------------------------------------------- Can anyone help me? Thanks a lot!! Terrence