I have just changed to Avast, after reading a complementary report in Computer Active Magazine.
Every time I switch on my computer Avast tells me it has intercepted a bug. On the pop up screen it gives the option of reporting a false positive. How can I know if it is a false positive? It names it 'BlT14F8.TMP Original location C:\ProgramData\374311380 Virus Win32:MalWare-gen or Win32:Adware-CAW [Adw]
How can I know if it is a false positive?test suspicious files here www.virustotal.com / www.metascan-online.com if tested before, click rescan post link to scan result here
That is highly likely an infection
Follows the steps Michael has advised
If this is a virus I do not know where it is, as the location given by Avast is an empty folder. So I cannot have it scanned by virustotal.com. Or any other place.
It is running from the bits programme on your system
Please download Farbar Recovery Scan Tool and save it to your Desktop.
Note: You need to run the version compatible with your system. If you are not sure which version applies to your system download both of them and try to run them. Only one of them will run on your system, that will be the right version.
[*]Right click to run as administrator (XP users click run after receipt of Windows Security Warning - Open File). When the tool opens click Yes to disclaimer.
[*]Select additions at the bottom
[*]Press Scan button.
https://dl.dropboxusercontent.com/u/73555776/frst.JPG
[*]It will produce a log called FRST.txt in the same directory the tool is run from.
[*]Please attach both logs generated.
Here are the requested files
OK lots to kill so lets get at it
Save the attached fixlist.txt, in the same location as FRST.exe
https://dl.dropboxusercontent.com/u/73555776/FRSTfix.JPG
Run FRST and press Fix
On completion a log will be generated please post that
THEN
Please download AdwCleaner by Xplode onto your desktop.
[*]Close all open programs and internet browsers.
[*]Double click on AdwCleaner.exe to run the tool.
[*]Click on Scan.
[*]After the scan is complete click on “Clean”
[*]Confirm each time with Ok.
[*]Your computer will be rebooted automatically. A text file will open after the restart.
[*]Please post the content of that logfile with your next answer.
[*]You can find the logfile at C:\AdwCleaner[S1].txt as well.
I am very grateful for your help. I enclose two log files, there wasn’t one with [S1] in the name, so I have attached the two that are there.
How is the computer behaving now ?
It could be faster, but that is probably just the usual Windows slowing down! I also had a visit from Windows Defender, telling me it needed to scan the computer. This is the first time I can remember seeing Windows Defender. It found no problems. I was surprised to see it ‘Burst’ into activity, would that have had anything to do with the problems I was having? All seems well now but as you may well advise me, I’ll keep an eye out for anything out of the ordinary - whatever that may mean!
Once again I would like to thank you for your help. I had been tempted to do a complete re-install, but was a bit daunted by having to tidy up all the things I wanted to save. 8)
You did have a lot of adware on the computer. Mayhap a disc defrag might help
Any further problems before I tidy up ?
Thank you! No I don’t think there are any more problems. I usually keep it fairly well defragged, but I will check.
Thanks again.
In that case methinks I will send you on your merry way 
Subject to no further problems
I will remove my tools now and give some recommendations, but, I would like you to run for 24 hours or so and come back if you have any problems
Now the best part of the day ----- Your log now appears clean 
A good workman always cleans up after himself so…The following will implement some cleanup procedures as well as reset System Restore points:
Remove tools
Download and run Delfix
https://dl.dropboxusercontent.com/u/73555776/delfix.JPG
: Keep Java Updated :
WARNING: Java is the #1 exploited program at this time. The Department of Homeland Security recommends that computer users disable Java
See this article
I would recommend that you completely uninstall Java unless you need it to run an important software.
In that instance I would recommend that you disable Java in your browsers until you need it for that software and then enable it. (See How to diasble Java in your web browser and How to unplug Java from the browser)
If you do need to keep Java then download JavaRa
Run the programme and select Remove Java Runtime. Uninstall all versions of Java present
Once done then run it again and select Update Java runtime > Download and install Latest version
https://dl.dropboxusercontent.com/u/73555776/javara.JPG
Now that you are clean, to help protect your computer in the future I recommend that you get the following free programmes:
CryptoPrevent install this programme to lock down and prevent crypto ransome ware
https://dl.dropboxusercontent.com/u/73555776/CryptoPrevent.JPG
Update and run weekly to keep your system clean
Click on the link above to be taken to Unchecky.com
click the very large Download button.
click Save
Click Open folder
Right click on the Unchecky_setup and choose to Run as Administrator
Once open click the Install button.
Then click on Finish
Unchecky is now installed and will help you keep unwanted check boxes unchecked, this is a fire and forget programme 
It is critical to have both a firewall and anti virus to protect your system and to keep them updated.
To learn more about how to protect yourself while on the internet read this little guide Best security practices Keep safe 