Hello! First of all thanks for your help. I am using Windows Xp with sp2. I saw the blue screen when browsing the internet. I use Kaspersky and Zonealarm and have been told that Zonealarm should better be updated in order to prevent this. I did. But it seems that the problem just occurs again and again. The parameters are : parameter1 00000007，parameter2 00000cd4，parameter3 02060002，parameter4 82d26a78。 Thanks a lot.