I have a samsung SyncMaster 2333sw monitor and everytime I put a new operating system on my computer (which is infrequent) i need to update the colour profile management so that white actually shows as white on my screen instead of an off white / cream colour.
To do this you need to change the ICC Profile that is default selected for your monitor.
I had to do this recently for Windows 8 however its very similar to do since XP.
1. Right click on your desktop and select "Screen Resolution"
2. Click on "Advanced Settings"
3 Click on "Colour Management" tab
4. Click on "Colour Management" button. (you will see something like this)
5. Check the "Use My Settings For this Device" tick box.
6. Click on "Add" under the ICC profiles (you will then get a list of colour profiles)
7. Select the sRGB IEC61966-2.1
8. Remove the prior ICC profile or set the newly selected on as default.
9. Restart your computer.
You should then now have white where white is supposed to be instead of cream (assuming you have calibrated your monitor correctly)