I have xp system, and the icon of microsoft security essentials disappear and i can't scan or update my computer

Might want to download some other antimalware type software and scan your system. Some that i would recommended would be: 1. MalwareBytes (Free for Scanner/Remover) 2. SuperAntiSpyWare (free for Scannner/Remover) 3. RootkitRevealer 4. Norton Internet Security (Not free but you can use it for 30 days to see if you can clean your system). 5. Kaspersky Anti-Virus (not free but you use it for 30 days to see if it can clean your systems). Watch an excellent video by Mark Russinovich on removing malware (its quite advanced): http://www.microsoft.com/emea/spotlight/sessionh.aspx?videoid=359 My Sister In Law had the same symptons on her computer. My neice had downloaded kazaa or another problem like and infected their computer like nothing else. Installing security essentials pretty much had the symptoms yous saying. The malware was shutting it down. There was a bunch of rootkits installed. I can tell you rootkits once they get embedded are very hard to remove. Anyways best of luck

Hi, According to the problem description, I realize that the operating system you have is Windows XP. In order to get the answer effectively, it is recommended to submit your question in Windows XP Service Pack 3 (SP3) Forum. Personally, I also would like to suggest you try to start Microsoft Security Essentials (MSE) from the Start Menu or the Program Files folder. You may also try to send the MSE shortcut to the desktop. If you find that the MSE installation is corrupted, you may try to uninstall and reinstall it to test the issue. If you also cannot update Windows XP, please refer to Windows Update Troubleshooter. Regards, Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.