Removing other Antivirus programs before installing F-Secure.
When changing from another AV to F-Secure, AV remnants can often be a source of problems when installing F-Secure.
These problems can be relatively minor such as a slowing down performance to major problems such as severe slowdowns/BSOD/cannot boot machine.
But the good news is that many vendors have specific removal-tools and if you completely remove your previous AV then your trial/use of F-Secure will be a much better experience.
As there are a lot of AV vendors, here are 3 choices to find your particular uninstaller link; which may be quicker to use than trying to find it on the vendors site!! This was the case even with F-Secure up to a few weeks ago!
1. Antivirus Remover; a great little application which I have recommended before. It contains the uninstallation program for any of the supported security software listed in the main window. Highly recommended, as the author updates the program nearly daily; http://www.softpedia.com/get/Tweak/Uninstallers/Antivirus-Remover.shtml
The download file is safe, and if you computer is 32- bit you will only see the 32-bit products in the list and the same for 64bit OSs.
2. List of Uninstallers; as the name suggests this is simply a link list of 26 common uninstallers; http://www.raymond.cc/blog/comprehensive-list-of-uninstallers-or-removal-tools-for-antivirus-software/#more-2878
3. List of Uninstallers; again a list to links; http://singularlabs.com/uninstallers/security-software/
Suggested removal of old AV and installation of F-Secure;
1. Remove old AV normally from Add/Remove/Programs and Features. Download specific removal tool. Reboot.
2. Use specific remover (preferably in Safe Mode). Reboot.
3. Install F-Secure; wait for ALL updates and until main Window shows that "all security features are up to date". Reboot.
However, if trying out a number of different AVs before F-Secure in a short period of time, I would recommend rolling back to a clean image restore after each trial instead of uninstalling/installing all the time.