There is a desktop background but can't enter the system.

Many people have appeared in the past few days when they have a desktop background but can't enter the system normally. Then, "Congratulations", you have a virus, here is a simple manual antivirus. Method, please try if you have the same situation.
First press ctrl+alt+del to open the task manager. There is a wsttrs.exe virus in the process. After the end, the desktop can be displayed. But it has copied a lot of files. The specific cleaning method:
Power on Press F8 to enter safe mode, enter C:\\WINDOWS\\, delete the following files:
mppds.exe, mscrrt.exe, winform.exe, upxdnd.exe, cmbcs.exe, cmdbc.exe, logo1_.exe, Wsttrs.exe and uninstall folder, clear all files under c:\\documents and settings\\username\\local settings\\temp folder
click “start”-“run”, enter regedit to open the registry , locate HKEY_LOCAL_MACHINE\\Software\\Microsoft\\Windows\\CurrentVersion\\Run, delete the key value containing the name of the deleted file.
The most important thing is to open the folder of the installed program and see the icon of the executable file become White DOS program icon, congratulations, please delete directly, use the installation file to directly install the overlay, do not uninstall, or the virus will be copied back, if more, then reinstall the system more directly, pay attention, non-system The executable file will also be infected, look at it, if you can't, delete
install the latest version of 360 security guards and kill it again. Use the startup item in the tool to manage to delete unnecessary startup items. After restarting, you may only be prompted. Can't find wsttrs.exe at a time, it's ok.
The last step, a full scan of the virus, I now know that Kaspersky and NOD32 can scan but can not remove the virus, can only delete infected files, backup important data antivirus: Q
PS: Kaspersky can use 360 The attached serial number is upgraded, NOD32 goes to the official website to download and then find a number on Baidu to upgrade the anti-virus.