If you start a new game and run around a bit, does the game crash within the same 3 minute time-frame? Does loading your latest save and leaving the warrior's guild to explore outside make any difference to when or if it crashes?
Since your other save is no longer crashing on load (as in your other post) it is probably an issue with the game itself, but duplicating the crash in a new game would confirm that.

Check out the topic Troubleshooting Tips (& manual install procedure).

For the slash4.dll error message, a couple people have had that problem when going through doorways, which lowering (or disabling) hardware sound acceleration would fix (click Start | Run, type in dxdiag and hit Enter, then switch to the sound tab).
Game crashes/Corrupted saves...

Another topic with slash4.dll errors; Crashes back to windows.