Difficulties after Windows Update

My PC is currently running Windows 2000 (yes, it's ghetto, but it's been stable for me). Not too long ago, someone suggested to me to update it to SP4. Since then, I have not done any further updates.

Yesterday evening, for some reason, I decided to see what kind of stuff I needed to update. I did the whole Windows Update thing from the windows menu. I found that I had 77 updates from Windows 2000. I d/led and installed them all and restarted the computer. Now, my Internet and Firefox don't seem to work properly. What I mean is that I'm getting "The page cannot be displayed" page on IE or "Address Not Found" page on Firefox when I try to load something like Yahoo or Facebook. Only when I hit refresh button about half a dozen times, will I actually get to the website. This has also affected my booting of MSN, as I would get some error msg with that too.

I've restarted the computer couple times already with no improvement. I've checked my Internet connection already as well. There are no problems with that whatsoever (b/c my brother's computer on the same connection is working properly). Someone suggested to me to use the "PageCannotBeDisplayed" program, but I'm hesitant to use some external program w/o really knowing what it is. I would like to stress that prior to the Windows Update, I had no problems with IE or Firefox. PLEASE help! If you require any additional info or scans, please let me know and I'll try to accommodate.