Current Nokia S60 handsets have only partial support for multiple windows. Although the S60 browsers support multiple windows, they do not support the ability to manually open a new window or the ability to open a link on a page in a new window. This site has a partial work around to allow users to open new windows
Add this bookmark to your handset: http://newtab.co.uk/
When you open this bookmark, click on the link in the page and your browser will open a new window
Using the bookmark technique is fine, but it means opening a new page. This means your browser will loose whatever page is currently open in order to open the bookmark. It is not great to have to open a new page just to open a new window. Another technique is to use the web feeds
The instructions here cover the N97 and E90, but this technique should work on many other Nokia handset that supports RSS feeds
Open the link, http://newtab.co.uk/ and select "subscribe to web feed"
On the N97, this can be done by selecting "Options", "Subscribe to web feeds"
On the E90, this can be done by selecting "Options", "Subscribe", "New Tab"
Now, after you have subscribed to the feed, you should be able to use the feed to open a new tab
On the N97, select "Options", "Go to", "Web feeds", "New Tab", "Open New Tab"
On the E90, select "Options", "Bookmarks", "Web feeds", "New Tab", "Open New Tab"
Now you can open a new window without loosing the page you currently have open!!
I used and loved using a Nokia 7710 handset for years and there are many features it had that Nokia seem to have lost. Multiple windows/tabs are one of them. I hope you find this work around useful, feel free to visit the thread on the Nokia Discussions to give me some feedback