You might try using the free
HOUSECALL online scanner from TrendMicro.com to scan for normal viruses, and then use their free
RootKitBuster anti-rootkit/anti-Bootkit virus scanner. This checks for boot viruses in the hidden partitions of your hard drive where most other antiviruses cannot check. Default settings in the free versions of most antivirus programs do not check for
rootkits/bootkits, such as in
Avast, or Malwarebytes, they must be enabled by going into settings and selecting the
"Check for Rootkits" option. The paid version of Malwarebytes is one several of us recommend, and if it's Real-time Protection option is selected, it will check for Rootkits automatically; otherwise it is turned off. I recommend the Avast Internet Security ($50/yr.) or the Avast Premium ($79.99/yr.). These products I've deployed in about 35 customer machines who have gotten hit by viruses or spyware viruses using other products, mostly free as Neemo states. Paid protection is your best bet, and Avast gives you the most bang for your buck. If you purchase their 2 yr. or 3 yr. combo package, the Internet Security package runs $27/yr. and the 3 yr. package of the Premium is $33/yr. I use both of these for my high-end Clients.
Another one I've begun using is
EMSIsoft anti-Ransomware. Their paid version is about $40/yr. and I'm deploying it now with Customers who have gotten hit by troublesome Ransomware and gotten locked out of their computers.
Even if you get one or more of the paid AV/Malware products that we recommend, it's not possible to predict whether or not the virus removal process will fix your Internet connection problem.
Before using any AV/AS scanners we strongly suggest that you FIRST BACKUP ALL OF YOUR PERSONAL DATA TO EXTERNAL MEDIA! THIS WOULD INCLUDE YOUR LIBRARY FOLDERS FOR DOCUMENTS, PHOTOS, MUSIC, VIDEOS, AND ANY SAVED E-MAILS OR ATTACHMENTS IN ORDER TO AVOID IRRETRIEVABLE DATA LOSS!!!
You cannot count on any AV/Malware product, even the paid version to fix all problems or subsequent damage from virus-removal on your computer, as it could have multiple problems, such as Windows Registry corruption or hardware failure (faulty Hard Drive or RAM sticks).
In this case you will need to first test your Hardware using my free
TROUBLESHOOTING GUIDE available here:
https://windowsforum.com/threads/unclickable-task-bar.222292/#post-676594
Once you've tested your Hardware and replaced any faulty hardware found and got all tests to pass, you can then look at doing in order a Windows repair, reset, or reinstallation from factory Recovery Media, as outlined also in the software section of my free
Troubleshooting Guide here:
https://windowsforum.com/threads/sound-problems.222287/#post-676549
Some viruses these days will not be removable using any free tools, and there are many poor quality ones out there, such as the Spyhunter you mention. And without many years of virus removal experience, even using free tools you may not be able to safely remove it, and thus the Huge Red Caution I have above about backing up all your personal data before attempting any kind of software repairs or even Hardware Testing. Clearly you are looking for the cheapest way to fix your problem, but, you get what you pay for, and we are trying to tell you short of paying
$45-$185 US for a licensed Tech to fix your problem, you should be using paid protection as Neemo and I both suggest. But, hey, it's your computer, so it's up to you if you want to spend weeks or months trying to fix your problem! Most of us professionals here have multiple computers, so if we get a nasty virus on one of them, we can just move to one of our other machines and keep on working.
Many folks here don't have that option, as may be your case. You should carefully weigh the cost of using paid versions of AV protection versus the cost of professional computer expert repair and how much your downtime is costing you in lost productivity: especially if your infected computer is your
ONLY computer!
Best of luck,
<<<<BIGBEARJEDI>>>>