In order to download a Windows installer on Linux, your browser needs to advertise itself with the correct user agent. The user agent identifies which browser and operating system you are using and is sent to each website you visit. This allows websites to adapt to your system, which can prevent you from downloading the correct installer type for use with CrossOver.
1. Go to the Firefox Configure Editor
Type 'about:config' in the address bar and hit enter. Select 'I accept the risk!'.
2. Add or modify 'general.useragent.override' preference
Enter 'useragent' in the search bar to filter your existing preferences. If the 'general.useragent.override' preference does not exist, right click on the preferences list and select 'New' and 'String'.
Enter 'general.useragent.override' as the preference name.
Enter a Windows user agent as the value of the preference. A complete list of user agents can be found here.
For example: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:39.0) Gecko/20100101 Firefox/39.0
3. Reset preference
The 'general.useragent.override' preference is permanent and will remain even after you close tabs or browser windows. To reset the setting, right-click on the preference name and select 'reset'. This will restore your default user agent.