I'm using Visual Studio 2008 and developing a VB.NET application. I'm having strange lockup problems with my program, but only when Internet explorer 8 is opened. When I cover my form with another window and then uncover it, I find that it has locked up. My program has no references to IE and the only thing it even has to do with IE is using Process.Start with a web address. My program works fine and exactly as it should, but only when IE is not opened. Does anyone know why a program would lock up only while IE is running? Edit: I've done some digging and I've found the offending thread in my program. I don't know what starts this thread or what it does, but when I kill it, my program no longer freezes. The thread is one of the CreateApplicationContext threads, here is the last few items in the stack trace of that thread. 6 ntkrnlpa.exe+0x897bc 7 ntdll.dll!KiFastSystemCallRet 8 mscorwrks.dll!LogHelp_TerminateOnAssert+0x61 9 mscorwrks.dll!DllUnregisterServerInternal+0x10523 10 mscorwrks.dll!DllUnregisterServerInternal+0x10542 11 mscorwrks.dll!StrongNameErrorInfo+0x34387 12 mscorwrks.dll!StrongNameErrorInfo+0x34815 13 mscorwrks.dll!CreateApplicationContext+0xbc35 14 KERNEL32.dll!GetModuleHandleA+0xdf Process explorer says my program is using no CPU nor throwing any exceptions while it is hung.