Try running the page set-up wizard.
Open TC, and at the startup screen choose new from scratch.
Do not draw anything, go to file menu - page setup wizard.
In the dialog box, on the first screen choose metric. Click Next.
Go through setting up the defaults, I'd suggest leaving most as default like Model space 1:1.
On the last screen tick the Save settings box, then click finish.
Close Tc, and reopen, click new from scratch, hopefully its now in metric.
As an extra note, you may wish to consider using templates, where you can set up everything how you would like it, i.e. Metric, some layers, colours etc. And save as a template (file type .tct), then when you start TC you can open the template and everything will be just how you like it. When saving as a template, Windows may prevent one from saving in the correct folder. If that happens, save it anywhere and manually move it using windows file explorer, into program files x86 - Imsi - TCW10 - Templates.
Hope this helps.
## Edited ## Just wondered, is your v10 Pro or v10 Standard/Deluxe. If Pro, I'd say go ahead and use it. If Standard/Deluxe (same thing just different names). I'd suggest considering upgrading (there are separate upgrade prices depending on current version) to a more recent deluxe, as you would get the advantage of 64 bit version (assuming your windows 7 is 64 bit) + many improvements. at, what I think is a very reasonable cost. ## End Edit ##