It's quite definite - I've done a system restore, got the up key to work in tcsh as expected.

Just to make sure it's not a 5.8 thing, I downloaded 5.12.0.1.msi and installed it to C:\strawberry

Fresh after the install, no reboot needed, I launched tcsh and after pressing the up key I get the dreaded '^[[A: Command not found."

Unlikely as it seems, what could be the cause?

I'll repeat the process tomorrow and do text registry snapshots before, but I doubt anything will be evident from the diff.

Just in