css sheet for explorer

Hi. At my site, [login to view URL], if you check the source code, within the head tags, you will see links for three css style sheets: The upper two style sheets, "[login to view URL]" and "Z-compliant-browsers" work selectively depending on the width of the browser window. I would prefer that these upper two style sheets not be modified, or if they are, inform me of any changes line by line. The last one for explorer, "[login to view URL]" is blank. If my site is opened in explorer, my layout and design disappears and the content and links are barely usable. I am not looking for a major site upgrade. I don't think my customers expect that of a handyman or for that matter, I don't think they want to see to much sophistication on my site. It would have a tenancy to make me appear expensive. What I would like done is to have the last css stylesheet, "[login to view URL]", pass into the css code whatever corrections that are needed to make my site display reasonably well in explorer. I understand that I might loose some of the shadow and rounded corner aesthetics of css3 if explorer doesn't work with css3, so to display "reasonably well" is all I'm looking for as far as explorer is concerned...