I have recently had a problem with my pc whenever i try and download anything i get the following message appear

"internet explorer can not download
internet explorer was not able to open this internet site.the requested site is either unavailable or cannot be found.

can someone help me with this please

Is this a new problem? Were things working OK previously? Any new hardware and or software?

If this is a new problem try a System Restore to a point prior to the problem:

start > All Programs > Accessories > System Tools > System Restore


Otherwise perhaps this may help:

http://support.microsoft.com/default.aspx/kb/816868