RewriteCond %{HTTP_USER_AGENT} (MSIE|Trident) [NC]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_URI} !^/unsupported-browser\.html
RewriteRule ^(.*)$ /unsupported-browser.html [R=302,L]
RewriteCond %{HTTP_USER_AGENT} (MSIE|Trident) [NC]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_URI} !^/unsupported-browser\.html
RewriteRule ^(.*)$ /unsupported-browser.html [R=302,L]