Look at what software program you are using, I.E. Mozilla, Internet Explorer. Make sure you have the latest download and if you are unsure of what you are doing go into the settings found in Tools and restore to defaults.
Close the program and then re open it, this should allow you to see everything, if not don't suppose you are on dial up instead of broadband? Or are you running several programmes and your RAM is struggling?
These are just the basics to start checking, most of the time it will rectify through just checking these.
Hope this helps.