400 bad request errors

Hi everyone,

Recently, i decided to install Windows Vista on my home computer. I
installed it on a second harddrive to play safe in case of any errors not
migrating to my original Windows XP pro installation. Anyway, i also bought a
bew graphics card and while i was playing with it ( OCing) they asked to
upload the scores.

This is where the problem starts. After i tried to upload these scores i
only got back errors. On every website i encountered i got errors saying Bad
request - 400.. All html errors. So i thought.. Ok, well , maybe i better be
switching back to Windows XP Pro. After i booted in XP, i tried using my
internetbrowser BUT AGAIN i get the errors. And i tried Internet Explorer (6
and 7 ) Safari, Mozille Firefox, Chrome and Opera. But nothing seems to
work.. Heck.. even google doesnt like me anymore..

Bad request 400 on EVERY webpage. After i hit f5 some times, it finally
shows portions of the website and its content. Even images like the google
logo are completely messed up.

So i decided to buy a new harddisk, install Vista on a clean, empty
Partition on my new Disk. So i went on installing the virus scanners and
spyware removers, After this i htought, now its safe to turn on my network
connection, but even NOW i get the bloody 400 bad request errors.. Im losing
my patience and i still havent ot the slightest on what could possibly be the
problem let alone.. solution.

It is not a network problem either.. the other laptops (windows and mac)
work fine on the internet.

Nor is it a DNS server problem. I used ipconfig/flushdns and i cleared the
hosts (windows/win32/etc/internet/ )

I also tried to reinstall my modem/router but the problem doesnt go away.

Any help is MUCH appreciated. I dont know where to look anymore and i
couldnt find any logic awnsers anywhere. That is why im turning to you.

Thanks in advance,

Merijn

(ps. Im not native UK/US so forgive me for any typo`s)