I had mathcad 5.0 working perfectly on my computer. I tried to install mathcad 6.0 and it got stuck at 1% and said there was a conflicting installation. I uninstalled 5.0 and I still got stuck at 1% when trying to install 6.0. Now when I try to re-install 5.0, it also gets stuck at 1%. I deleted the program files\PTC folder and checked appdata for other PTC folders. I'm not sure what's blocking the installation. It also says that .net framework and the other program it needs to install are already installed. The error it gives is something like 'please check logs'. The logs say Error 1622 after trying to do something with the PTC file.