Starting with version 7, WinEdt does not support YandY TeX anymore, so, if you're still using this obsolete TeX System, this is the right package for you.
Open the macro file Install.edt in WinEdt, and execute it by choosing Macros | Execute Current Macro. YandY TeX configuration will be added in Options | Configurations menu.
Open the macro file Uninstall.edt in WinEdt (also available in %b\Uninstall\YandY TeX folder), and then execute it by choosing Macros | Execute Current Macro.
After the installation you should be already in YandY TeX configuration and can start using WinEdt with YandY TeX. Avoid using accessories that are not bundled with it (eg. PDFLaTeX).
For WinEdt 7.x: YandYTeX_7.zip
For WinEdt 8.0-8.1: YandYTeX_8.zip
For WinEdt 8.2, 9.0: YandYTeX_9.zip
For WinEdt 9.1: YandYTeX_91.zip
Configuration contributed by Karl Koeller <karlkoellergmail.com>.