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.

Another cause can be due to the operating system's PATH exceeding 250 characters. This is not due to the Adv/TAS executable (tpc50.exe) per se, but rather due to the DOS4G.EXE that it first loads. At a CMD prompt type PATH to determine if that might be the cause. If it is lengthy, try clearing the path by typing SET PATH= (and nothing after the equals sign) and press ENTER. Then see if tpc50.exe (called usually by a batch file, ADV.BAT in the case of Advanced Accounting, R50.BAT or R51.BAT in the case of TAS 5.x after checking to see to what extent there are SET PATH= statements in those batch files) will then load. If it does, then add/edit SET PATH= statements as appropriate to shorten the path on the PC where it fails, or modify the environment variables. More information about DOS/4G path too large.

If you are trying to run tpc50.exe under a 64-bit platform and it is in that environment that it is not loading, see Windows 7 compatibility.