If you were already infected, you might try scanning with an offline
An example, is the CD ISO9660 file here. You need a CD burning program,
that converts an ISO9660 file into a bootable CD. Something like
1. Iso image of Kaspersky Rescue Disk 10 (196 MB)"
Even if you cannot get the virus updates, when that disc boots,
the scan may still turn up something. The disc is designed to
connect to your modem/router, using DHCP to get an IP address
automatically, then download virus definitions from Kaspersky
before the scan starts. Then, you tick all the partitions in
the scan box, and let it go, and see what it turns up. The disc
does not have support for dialup networking that I could see,
so it really helps to have an Ethernet cable to your Internet
That disc is based on Linux Gentoo, so when the disc is booted,
you are running a copy of Gentoo. And then the Kaspersky scanning
program runs and checks for Windows malware. It might even be
able to detect things like TDSS rootkit.
Being an offline scanner (i.e. Windows is not running at the time),
it avoids many of the issues with "getting things to start". That
is the main reason I like it. None of the problems getting
things like Malwarebytes (MBAM) to run, or seeing the symptoms
you are seeing.
You can also try running MBAM, and if it will not start either,
then you would suspect malware is already present. MBAM is a
Windows program, to be run while Windows is running.
removes malware when started manually"
If you cannot reach their website, go to another computer
and download MBAM. But when you bring the executable over,
it still might not run if malware is present. The malware
designers are very aware of MBAM, check for its name,
check for code of that nature, and so on.
I'd bring the file over on a CD, to reduce the risk of
contaminating a USB stick.