Hi, I'm running on XP home. I downloaded the Serial communications toolbox, and put both the .dll and .dlm in C:\Program Files\ITT\IDL71\bin\bin.x86 However, when I try any serial commands (comm_open, comm_write, etc.) a window pops up and says " This application had failed tos tart because Idl32.dll was not found. Re-installing this application may fix this problem." Also, I get the IDL error: COMM_OPEN: Error loading sharable executable. Symbol: IDL_Load, File = C:\Program Files\ITT\IDL71\bin\bin.x86\serial.dll The specified module could not be found. I tried re-installing IDL to no avail, and the .dll is definitely where the error says it isn't. Any ideas?