I am trying to download from this site; http://unity3d.com/unity/download/ and get this message: “Unity requires Windows XP or later”. It has an OK box to check after that.I have Windows 7 Professional.
Hi, I was running into the same error, getting the “Win XP or later required” message and then the installer closed, when trying to install Unity 3.5.7 (downloaded from http://unity3d.com/unity/download/archive) on Win 7 Home Premium 64 bit.
However, I found that the installer ran successfully after running the installer exe as an administrator. You’ll have to navigate to your downloads directory and right-click on the file and choose “Run as Administrator”. Once I did that I was able to complete the install. Hope this helps!