msabet,
Many possible causes.
We need to start ruling out possible causes. This will not be painless, this will not be instantaneous, I've not magic wand. What I do have is a long and tedious procedure that will get you there.
Let's start with ruling out viruses.
Carry out following, after you finished with that step, then let us know and we can proceed. No jumping around to a "quick fix".
HOW TO USE WINDOWS DEFENDER OFFLINE ON A USB STICK
Windows Defender Offline
· is a
free standalone,
bootable malware and virus remover from Microsoft.
· performs an offline scan of an infected PC to remove viruses, rootkits and other advanced malware.
Download Windows Defender Offline (about 764 kB)
You will have the choice of downloading the 32bit version (x86) or the 64 bit version (x64).
The link will help you determine whether you are running a 32 bit version or 64 bit version of Windows
NOTE!! You can download and prepare a 32 bit version using a 64 bit version of Windows
NOTE!! You can download and prepare a 64 bit version using a 32bit version of Windows.
You run the 32 bit version on a 32 bit version of Windows.
You run the 64 bit version on a 64 bit version of Windows.
The 32 bit download file name is:
mssstool32.exe
The 64 bit download file name is:
mssstool64.exe
For the curious, this program was originally name
Microsoft
Standalone
System
Sweeper.
INSTALLATION:
You will need an Internet Connection.
Insert 512 mB (Microsoft’s 256 mB is no longer accurate) or larger USB stick into a usb port.
Run the downloaded program--
mssstool64.exe or
mssstool32.exe
NEXT button
Choose the option
On a USB flash drive that is not password protected
NEXT button
NEXT button
.
The install program will format the usb stick using the NTFS format.
The install program will download about 210 mB.
The install program will name the USB stick
WDO_Media32 or
WDO_Media64
The WDO_Media32 usb stick will have used space of 255 mB (268,140,544 bytes)
The WDO_Media64 usb stick will have used space of 282 mB (296,165,376 bytes)
You can expect the number of mB to increase as more malware appears.
UPDATE Windows Defender Offline USB stick:
· reinsert the usb stick
· run the installation program,
mssstool64.exe or
mssstool32.exe, again.
· the update will download about 66 mB (mssstool32.exe) and 68 mB (mssstool64.exe).
Since the malware database is sometimes updated several times in a day, always update before running.
PERFORM AN OFFLINE SCAN
Bootup your computer from the USB stick
Windows Defender Offline will automatically perform a
quick scan.
After the quick scan finishes,
Choose Full Scan
Select
all of your drives
The initial,
full scan can easily take several hours, but
Remember, your computer is being very thoroughly checked for all types of malware.
RESULTS OF THE SCAN
The results will be in 4 log files on your computer's disk in:
\Windows\Microsoft Antimalware\Support
msssWrapper.log, (reveals start and stop time of WDO)
MPDetection-dddddddd-nnnnnn.log, (version of detection engine and AV database)
MPLog-dddddddd-nnnnnn.log (scan summary), and
MpCacheStats.log.
Upload the four log files please.