Help I keep getting this "page cannot be displayed" when I try logging onto the internet.?

How long has it been since you cleaned your disc of unwanted files. Try this, go to MY COMPUTER right click on the "C" disc and click on PROPERTIES, then click on CLEAN DISC, it might take a few minutes to load this part, then when it is up, click on the appropriate items that have big numbers in it, then click OK, it will ask you if you are sure you want to do this, click OK or yes then wait a few minutes for the computer to do its thing.