Originally Posted by craigevil
Also what OS?
If it's an EeePC, it's got a customised Xandros installed.
I had no problems accessing Gmail or Hotmail (don't have a Yahoo! account) when my EeePC had its default installation on it. Have you tried clearing all the private data? Open Firefox, go to Tools, then click on "Clear Private Data". Make sure the Cookies tickbox is ticked, then click "Clear Private Data Now".
To check whether you have cookies enabled, open Firefox, go to Edit, then Preferences. Make sure the "Accept cookies from sites" box is ticked. Also, check in the "Exceptions" box that Gmail or Yahoo aren't being blocked in there.