Reinstall Windows, might fix it.

It may be the case that the pages that load very fast are cached into the computer's system, which enables if that website is loaded again, the content that was cached loads very fast - content that is new on the site.

With YouTube, if you wish to view the same video again, it has to retrive that video again from the server, the file is WAY to big to cache into the system.

Suggestions:
Watch YouTube on a lower pixel size (I use 240p, cause I stretch 6GB a LONG way, 6+ days)

Don't keep resetting the browser's settings if it runs slow (If you need to, DON'T DELETE THE CACHE!!! Only history and stuff like that)

Look into getting a YouTube video downloader, instead of when you need to watch the video again, you don't have to load it again. I suggest RealPlayer, as it has a pre-installed downloader + converter as the files download as a .flv file, which means you can convert the files.

That's my 2 cents on the issue.

When I had my old laptop, what I used to do is remove caches, cookies etc in the settings page of whatever browser I was using at the time. It helped a lot for me! Hope it works for you as well!

What's your internet connection anyways? DL speed.

That always happends, I get around 15MB/S and I download games around 2mb or 3mb if it's a good day. Youtube has been slow for me lately too. Either it's their fault or we both have the same problem

Most likely the case.

youtube disabled the ''Pre Buffering'' it annoyed me 2. but i found a little pluging for chrome








pssst it's here

Sure, no thing. Glad i could help a little.