What operating system and version you are using. CHIRP works on all platforms. I'm using Linux but it works on Mac and Windows as well.
Tell us what radio you are trying to program? If it's more then one, pick one so we can get that working first, the others will follow.
Tell us what kind of cable you are using. There are some problems with counterfeit cables - it's not a CHIRP problem but there are Chinese made adapters that use fake chips using the Prolific chip. The FTDI chip based cables work fine. See http://chirp.danplanet.com/projects/chirp/wiki/CableGuide There is also a work-around for the automatic driver update that Windows does that will allow your counterfeit cable to work by rolling back the driver.
Let's start there and see if we can add you to the happy CHIRP user base.