Help guys, I have windows xp pro at home and when I try to instal mirc603 i get this error message "mirc603.exe is not a valid win32 application"
can someone help

Looks like the download is corrupted in some way. Best to scrap it, download it again, maybe from a different mirror just to be sure.

maybe you used a bad download site, or maybe you accidently overrided you mirc with a note.