Hello,
How are you trying to get to that site? Are you typing in the address by hand? or using a shortcut?
That's to say, make sure the website address is typed in correctly.
Does this pc even get to the first (home) page for play.com ? Or is it always showing "400 error" right away?
On IE menu bar, select View, and check Status Bar to have it on. Having the status bar visible will not cure the problem, but is a very handy visual clue to the progress of the attempts to access a website.
This is the technical description for a HTTP 400 error:
400 Bad Request
The request could not be understood by the server due to malformed syntax. The client SHOULD NOT repeat the request without modifications.
It would seem your browser can reach the site, but something is being "corrupted".
One suggestion: Make sure you clean out your temporary internet cache files (on the off-chance your cache is over-full or causing a corruption).
See
http://mvps.org/winhelp2002/delcache.htm
Then try that site again. (p.s. That site takes a good while to load).