Tracking a Cash ISA
Because most of the account types in Microsoft Money are pretty generic, you can set up a Cash ISA in Money quite simply.
By far the easiest way is to create a regular savings account. This is tracked as a bank account, and you can do anything with this savings account as you need. You can create it by starting Microsoft Money, going to the account list and pressing the option on the left to 'set up account'. Tax is only relevant when you get your interest, so as long as you don't put any in, there isn't a problem.
In the UK version of MS Money, it is also possible to use the "savings centre" to track this account. To use this, instead of creating the account through the usual account setup, as you would above, you can set it up in the savings centre. This can be done by selecting the 'Planning' option, followed by the 'Savings Centre' option on the Planning tools dropdown menu.
This still does the usual account setup, but using the savings centre will also allow you to specify contribution limits and estimate the future value, which you don't get by using the standard account setup.