v., win·rot·ted, win·rot·ting.
1. The inevitable creeping, pernicious degradation of the integrity of Windows systems to the point where they run slowly, behave erratically, or stop working altogether.
1. To cause Windows to decompose or decay. “Adobe Reader winrotted my fresh install”.
1. The process of Windows rotting or the condition of being rotten: “The winrot spread quickly, rendering the system slow and unstable”.
2. Any of several Windows programs characterized by the breakdown of stability, speed or security. “Don't install Norton. It is absolute winrot”.
My nephew only used my computer for 10 minutes, but once he was done the winrot was so bad I had to reinstall Windows.