You've renamed the file to *.txt and you're using file|Open to open the .txt
file?

I have a text file, and its extension is txt. I did not rename it, in case
it matters.

I've never seen this fail to pop up the text to columns wizard.

Then, I guess, it must have been deactivated on this machine.
Could you tell me how to turn it on?

Can you provide more detail?

Windows XP SP2
MS Excel 2007