I checked "OS2.INI -> PM_Workplace:Startup"... I didn't understand the stuff there, so I deleted the two values inside it. On the next boot the folders that auto opened where gone.
One entry should remain. It's that one from the current startup folder. If you use XWorkplace's startup folder(s), you don't need it, of course.
Some steps of my previous post explained (I use Initor):
1. OS2.INI -> PM_Workplace:Startup
-> This ini application has the key name 'C779' on my system. Its value is '59 00 00', which stands for the letter 'Y', followed by 2 zero terminators.
-> You get the corresponding WPS handle of that startup folder if you prepend a 3 to the key name. That gives the hexadecimal WPS object handle '3C779'.
2. The next step is to open the properties of your current startup folder and to find the WPS handle there. (This works only if you have eWP or XWP installed.)
-> Open the properties dialog of it. Select the 'Icon' tab. Press the 'Details...' button.
-> In the tree under 'Details' you find the item 'Object handle'. It shows in my case '0x3C779'.
-> That is exactly the handle from the key name I got from OS2.INI -> PM_Workplace:Startup.
If you have more than one Startup folder entries, you should remove the wrong one(s) and keep the only correct one.