Error message 1324 and 1603

Hi ! I am taking accounting software class this semester and have a problem to install your program in my computer. 

I'd installed Sage50 2018 version for this class on May, but I didn't use at all because I'd dropped it. Now I decided to take the class this semester and tried to install Sage50 2019 and got two error msg. It says 'An update has been detected on your computer, which may affect one or more files that Sage 50 users. You should install the update and then restart your computer  before installing Sage 50.' so I deleted old version (2018), and try to install 2019 again and there are two error code : 1324 and 1603. I don't know what to do.