I agree, littlestkiwi and ScaredOfCows. You can even create another "User" account for visitors, which has no access to files and e-mails, but which can use all the computer's programs (internet, games, etc.).
If you are using Windows, go to START (bottom left-hand corner), then SETTINGS - CONTROL PANEL.
At this point, it will depend on which "view" you have set up.
If "Classic" view, look for the icon for USER ACCOUNTS.
If the other view, the menu you need is USER ACCOUNTS AND FAMILY SAFETY.
This menu will allow you to password-protect your account, and also to set up another account for visitors. If you are very savvy, you will open the Internet Explorer program in that account and set it to keep history for 20 days! 
Once the new user account is set up, you can use the START menu again, whenever you want to switch between users.
By the way, you haven't made any comment about the idea of booking an appointment with another solicitor, to have the option of another solicitor waiting for you should the first one not be suitable. Please, please do do this, as it would be awful to have to wait ages for another appointment, when you are already waiting until January 10 to have this one.