Anti Virus Software
BBL recommends that a virus protection program is install and running on each computer in a shop, particularly when the computers have access to the internet and/or email. Use popular programs like Microsoft Defender. Consider updating the settings so virus definitions are updated hourly.
Anti-Virus software should not monitor the TW.EXE file which is the main program file of ProfitSystem. Monitoring of this file will slow it's execution down significantly. Each AV program has setup options to EXCLUDE specific files from monitoring. When you have trouble setting this up just contact the AV software manufacturer for instructions. Insure the TW.EXE file is excluded.