This might be better written as:It is unnecessary to install all possible anti-virus programs, you have to choose one (we suggest using *insert 1-2 fine antiviruses*), update it's databases and scan your computer.
It is unnecessary to install more than one anti-virus program, as this can lead to conflicts. We suggest installing one of the following:
- AV-1
- AV-2
After installation, please ensure you update the program's database to the latest version, and carry out a full scan of your computer.