FOSS gamedev and creative worlds

There is a particular mod which I am trying to delete to install the latest version. The problem is it keeps saying 'cannot delete because the file/folder is open in another program'. This is annoying, because the only program open is the dialog box giving this message. I have checked the task manager and I can't see any minetest processes running-help? BTW I am on windows 7 starter, with 2gb ram intel atom 1.6ghz processor.

Typical tech support answer, but did you try to restart and delete it first thing when windows starts?

Also check you computer for viruses.

Ah, thankyou. I resarted and it has allowed me to delete the folder. A short while after I couldn't delete it, and before the restart, my computer crashed. Shortly before this the scroll-wheel also stopped working. It all works fine now- may have been because my laptop stays plugged in and on standby for sometimes weeks at a time. This probably messes it up.