Suggest you download windows cleanup assistant to check and kill malware and Trojan horse (please search and download, don't use 360 Defender instead):
Download 360 system first aid kit to scan the system
1, please use the system comes with the system restore, restore to you do not have this failure to repair the time (or use the restoration software to restore the system, if you can't get into the system, press F8 to enter the security system, then press F8 to enter the security system. system, boot up and press F8 to enter safe mode to restore the system).
2, if the fault remains, use the system disk repair, open the command prompt type SFC /SCANNOW Enter (SFC and / between a space), insert the original system disk repair system, the system will automatically compare the repair.
3, if the fault remains, in the BIOS set the CD-ROM drive as the first boot device to insert the original system installation disk by pressing the R key to select the "repair and installation" can be.
4. If the problem persists, it is recommended to reinstall the operating system.
Use the system comes with the system restore method:
System comes with the system restore: "Start"/"Programs"/"Accessories"/"System Tools". "System Tools"/"System Restore", click "Restore my computer to an earlier time", press next, you will see the date page has a dark color date, that is the Restore point, you choose, click Next to restore (Win7 restore system, in the Control Panel then Devices and Security sub-options then Backup and Restore Options).