You were using mIRC with some scripts installed. You will have to locate those scripts again, and install them again.
If, for some unfortunate reason, the scripts you were using came bundled together with mIRC, then I can certainly understand your confusion. This is why scripts should never come with mIRC bundled together,
because people will assume it's a normal part of the program and never learn about locating and installing their favorite scripts later on.
Hope you find it again, or figure out how to write your own cute scripts like it!