I've used AutoCAD since version 2.52, and with Windowblinds for almost 2 years now (Versions 2000i, 2004 & 2005) I can't remember a single instance where I could attribute a crash in AutoCAD to Windowblinds. If you can feed me a little more info on what the circumstances were at the time I'll try to help. Which version do you have ? the free version or full version? You should have an error log and stack dump from the crash. It might help to know what's listed in the log. It's usually located in the same directory as the file you were working on at the time.