You may have to access this via the Start button on your PC (found in the bottom left hand corner of your screen) and find the Windows System folder - where you will see the Control Panel shown - as shown below:
Make sure you have selected your default email client as shown above.
Please note: if Outlook is not shown as your Email default please click on the option that is shown and normally you can then choose your default email client from the list of what is available (as shown below).
Once you have done this then go into your CRM account and send an email through it by clicking on a persons email address on their business card and it will pick up your default email Outlook client.
Once the email has been sent you will see it in the history of the contact you have sent it to.