i know, puters can seem overwhelming sometimes! Lets try this, first read
this part of mIRC's website just to help you understand a bit better whats going on and why its important to fix it no matter how confuzzling. Then i would go to
trendmicro's web site and run their free online scanner. It will tell you what it finds, and also have info at their site that will tell you what if anything else you need to do. Be patient, it may take a while to load and run, but dont worry, its safe.
There are cleaners you can download and run, but without knowing the exact prob its hard to say which may do the job for you. There are also channels on some networks where the ops (the ppl with the @ beside their nicks) are very knowledgeable and can help you one on one, like on DALnet #nohack and on Efnet #dmsetup or #mircfix.