Lets try something. Could you please run a pre-boot antivirus program such as Kaspersky Rescue Disk. This will run before windows loads so can remove virus's and malware more effectively. Instructions here: How to record Kaspersky Rescue Disk 10 to an USB device and boot my computer from it?
. It is also possible to use a blank DVD to run the program if you have no USB drives. Instructions here: How to record Kaspersky Rescue Disk 10 to a CD/DVD and boot my computer from the disk?
EDIT - This tool may be more effective. Windows Defender Offline