I am NOT looking for multi-currency support. I want only one currency other than USD for this file.
Is this possible? and if yes, how?
The only way that's possible in a US version of Quicken is to use a feature level which supports Multi-currency.
To change what you call the "base currency" go into Tools / Currency List while that file is open, click to select the desired new currency and click the Home button. The green checkmark in the Home column should now appear in the selected currency.
All existing account registers will retain the currency in which the accounts were created, but the Account Sidebar totals will now be converted to show the new Home currency.
Reports containing information about accounts of multiple currencies will now show all transaction amounts converted to the new Home currency. When customizing each report you can select a different currency if you so desire.0