For about a year we have been aware of an XP SP1 update that causes Advanced Accounting 5.1 and TAS 5.1 (TPC50.EXE, i.e. DOS mode only) to stop loading. A PC that was previously working without incident then fails to load the software after the update is installed, typically through an automatic Microsoft update. The program will start to load but does not get past loading the DOS4G.EXE and then quits back to the desktop.

The offending update appears to be SP1 Version 5.1 (Build 2600.xpsp2.050301-1526). You can determine the Windows build number by clicking on Start then Run and then type WINVER and click on OK.

The problem is resolved by either rolling back to a prior update or by updating to SP2.

See How to configure and use Automatic Updates in Windows XP (Microsoft article ID 306525) for more information.

Users may want to consider turning off Microsoft automatic updates.