I am trying to uninstall farcry from my hardrive but it just stops working and won't let me then I get a fatal 1603 error,  can anybody help me with this problem please,  many thanks.

Run the Fix-it application:

Fix problems that programs cannot be installed or uninstalled

Thank you for your reply S.Sengupta,  but please what is the fix-it application.

Thank you for your reply S.Sengupta,  but please what is the fix-it application.

This is an application which when you will run it will fix the problem automatically. In the above KB Article press on Run now to execute it.