Confirmed: It's entirely possible to have both KT200 and TagFlash installed on a single computer or PC, but need to switch the driver. Also TagFlash can be installed with other ECU programmers and also need to switch the driver.  Each software requires its dedicated driver to work. 

Therefore, there is no need to buy new computer, If your PC is compatible with KT200 and has successfully run it in the past, it will undoubtedly support TagFlash as well. 

With relay click sound will work normal as my device did, If not succeed you try uninstall both kt200 & tagflash driver. 
Website download link: https://www.ecuhelpshop.com/pages/downloads/ 

Oliver WhatsApp: + 8618205996549