Scribus document window opens off screen

I'm using Scribus Portable on a thumb drive. The properties and align palettes are visible, but I can see the main document window opens on the far right, off the monitor screen.
I Googled ways of moving the window back using Windows shortcut keys, but they didn't work. I also tried using the various options for arranging windows using the Windows taskbar, but they only rearranged the windows that are already visible on screen.
Since it's portable, I had been using the app on a PC that is set up to use two monitors as well as my own laptop at home (which is only one monitor), so I thought it had something to do with that. I thought I would be able to open it on the PC with 2 monitors and just move the window to the default monitor so I would see it on my home laptop. But the document window won't even show up with 2 monitors. It still opens off-screen on the right side of the right monitor.
Is there a way to fix this, either from Scribus or from Windows? I saw on another thread in the forums at the Scribus site, someone suggested editing the Scribus preferences in Notepad and it gave the address on where to find the Scribus preferences in Windows. But since I'm using Scribus Portable, the address isn't the same. I thought I found the Scribus preferences file on the thumb drive, but when I opened it I couldn't find the line it said to look for (I think it said to look for a line containing "