I know they say XP will run in 128Mb, but you'll barely run the OS on that, let alone a memory intensive programme.
First off, stick at least another 128Mb inside. Better still, replace your present memory with a new 256Mb stick so you don't need to match the old one. If your old motherboard needs 2, replace them both with new 128Mb sticks, theyl cost about £14 each, 256Mb sticks are about £27. -
Microdirect
Secondly, with the age, the software was probably written for Win95/98. Run it in emulation mode. Go into My Computer and drive down to the programme .exe file. Right mouse click on it and select Properties, then Compatibility Mode, then select Win95 and try it. You can try Win98/Me but you seemed to have problems there as well. But at least it would put you back where you started.
Thirdly, what's the programme? Have there been any patches/updates to it for newer OS? Give us the name and version so we can check.
Reference launching the programme.
1. Right click the programme under Start - Programs and create a short cut. Drag it to the desktop and start it direct from there.
2. If you really want it on a toolbar, XP has a Quick Launch toolbar in the taskbar across the bottom. If it's not already there, right-click an empty area on the taskbar, click Toolbars, and then click Quick Launch. To add items to it, left click and hold down on the shortcut icon on the desktop and then drag it into the toolbar.