The following behaviour has been observed by Warp2Search editor-in-chief. This is no bugreport just a description of facts that one particular PC was presenting. After installation of Windows XP Service Pack 1 initially downloaded from the premierdownload.microsoft.com site and succesful installation of SP1, beta Detonator 40.41 was installed for testing purposes... 40.41 was then uninstalled again after a couple of days and Windows XP did not revert back to standard VGA driver but instead loads a driver called Nvidia GeForce 4 Ti4600 (Microsoft Corporation). This driver is 29.58. Funny enough... So you already see that Windows XP SP1 does not let you go back to standard VGA. Well I can live with that I thought and went on to install WHQL certified Detonator 30.82 freshly downloaded from Nvidia. Upon installation of 30.82 WHQL I was greeted by a popup window that this driver has not completed Windows Hardware Quality Labs certification... Pardon me, Microsoft??? Even in device manager all files are displayed as not digitally signed. The problem seems to lie within an unrecognized security certificate. Maybe the algorithm has changed in post SP1 installations. The initial problems with the video drivers (stuttering in 3D applications with 40.41 Detonators) were traded to intermittend freezes with non-recognized WHQL certified 30.82 Detonators. If you have similar experiences please leave a comment.