No offense taken, however the problem is not with mIRC. The "real" mIRC must be downloaded and intentionally installed, and can be easily uninstalled thru windows. I'm afraid you have somehow gotten one of the many trojans that regretfully drop an old version of mIRC as part of their payload. Please understand that we are in no way affiliated with the creators of those trojans. Uninstall wont work in this case, you have to remove the trojan. Altho some virus scanners will clean a lot, it may be that you will also have to remove some files yourself, depending on what trojan is involved.
I would suggest using the free online scanner at this web page
as it catches some IRC type trojans others may miss. Make a note of what is found, and that site can also give you further info in case you do need to take further action beyond what they can remove. I wouldnt want to guess which virus/trojan is involved, Trojan.IrcBounce, WORM_HORSMAN.A, gbot types are among the common ones. You can find some additional resources at this web page
and at our web page
Using our search feature, setting it to all forums, all dates will show you many other threads with the same prob.