Hi L.Kay.
I don't know what version NetSupport School you had but I would recommend trying the new version (10.1).
Things have improved in versions released over the last few years, in that if a student reboots their pc, when it starts up again, the Tutor settings are picked up again. So blanking the screen will re-appear if that is the setting made by the Tutor.
There have also been improvements with internet & application blocking over time due to the introduction of new technology.
It won't cost you anything to try it out for 30 days, just visit the website to download for free. Netsupport School The Classroom Management Software
Also - if you had NetSupport School previously, depending on when you first purchased it, you may get a reduced price if you decided to update to the latest version.
Hope this helps.