When im in the inter net and i scrool down it is scrolling down by steps?

i used to have windows vista on my compaq pc. and i installed xp pro on it it works fine but when im on the internet and stuff when i scroll down its slow and u can see lines and when you move a window its slow. some people told me to update my graphics drivers but how do you do it? i have a compaq computer please hel it is anoingWhen im in the inter net and i scrool down it is scrolling down by steps?Slow window drag can be partially remedied by not 'showing contents' as it is dragged. It takes a lot of CPU power to render the entire window contents, so it tends to be slow, especially with a modest CPU/graphics card.

Start%26gt; Control Panel%26gt; Display%26gt; Appearance%26gt; Effects; here un-check 'show contents while dragging' %26gt;OK

Try using the 'Page Down' key to alleviate the scroll lag, if that's possible for your requirements.