IE 8 Security Settings
IE 8 allows you to group web sites into different categories where each category corresponds to a security zone. Then, each zone has its own security parameters which you can adjust according to your needs. To open Security settings, click Tools from IE 8, then click Internet options and finally click on the Security tab. The different security zones are as follows:
Local Intranet: Internal web sites that are accessed only by the internal users, such as, an organizational Intranet. By default, IE detects intranet sites automatically. However, you can add web sites to this zone by clicking the Advanced button of the Local Intranet sites dialog box. The default security level of this zone is Medium-Low but can be modify through the slider.
Trusted Sites: This is the zone for web sites that require elevated privileges, so make sure that you add web site that you trust here. By default, the security level is set to Medium while it requires all sites to be secure with a Secure Sockets Layer (SSL) certificate.
Restricted Sites: The default security level for this zone is set to High, so web sites in this zone are potentially malevolent. If you need to visit sites that you do not trust then add them to this category. Protected Mode is enabled for this zone which means that running web sites are given the lowest privileges as to protect other applications and the system.
Internet: Web sites that are included in the previous zones (Local Intranet, Trusted Sites and Restricted Sites) fall under this category. The default security level is Medium-High while Protected Mode is enabled. Web sites in this zone are unable to make changes to the system while they are blocked from viewing private data from other sites.
Although, the default security levels are in general adequate, however, you can use the Custom Level button to configure your own customized level. Settings include scripting, ActiveX control behavior, etc.
The Advanced tab of the Internet options window has configuration settings that apply for IE in general. The security options are found under the Security node (with an image of a padlock). The default settings for SSL/TLS versions, certificates options and authentication should be sufficient. However, I would check both Empty temporary Internet Files Folder when browser is closed and Warn if changing from secure to non secure mode.