1. Run installer (mirc727.exe or mirc729.exe)

Installation options:
- Path: c:\mirc727 or c:\mirc729
- Installation type: Full
- [ ] Add Desktop Shortcut
- [ ] Add StartMenu Shortcuts
- [ ] Backup Current Files
- [ ] Automatically Check for Updates
- [x] Run as Portable Application

2. Start c:\mirc727\mirc.exe or c:\mirc729\mirc.exe

3. Click [Continue] on greeting dialogue

4. Close mIRC

5. Start c:\mirc727\mirc.exe or c:\mirc729\mirc.exe again, and entire OS immediately either freezes up (a la 100% CPU use) or BSODs with:

STOP: c000021a {Fatal System Error}
The Windows Subsystem system process terminated unexpectedly with a status of 0xc0000005 (0x7c911f6c 0x00ebef80).
The system has been shut down.


This is repeatable for me. The BSOD (or freeze) occurs every time mIRC is executed for the second time. The issue has never occurred on this system with previous versions of mIRC (i.e., I can start and re-start mIRC 7.25 an infinite number of times on this system without problems).

This is occurring on a Windows XP SP2 machine with no Microsoft updates applied (except KB893357) and no anti-virus or other security software. (Please, no lectures; the system is used for development testing.)

Needless to say, the issue does not occur on any of my other machines, including a fully updated XP SP3 machine.

Khaled, can you think of anything that changed after 7.25 which might be responsible for this?

Can anyone else who has XP SP2 test for the occurrence of this bug?