Microsoft has posted the release candidate of Windows XP Service Pack 3 to its download site tonight.

It follows testing from several thousand invited users. According to a company spokeswoman, the version is a "release candidate" and will be available from the Microsoft Download Center. The final version of Windows XP SP3 remains slated for delivery sometime in the first half of 2008.

Microsoft has been downplaying the significance of Windows XP SP3 which some are claiming will be much better than its Vista product. XP SP3 currently is 580MB in size, but when it is downloaded and installed via Windows Update it will be about 70MB.