Well, i think I found the GUI you were looking talking about, and after brief searching, I found a download for it (I hope I did lol). I ended up downloading it myself and trying it out, while at the same time I moved my personal folders out onto my desktop, so I could see what folders/files would return.
Well after 10 minutes of goofing around, waiting for my slow hard drive, I realized I could just download the .exe and extract the files into a new folder to see the files needed to be deleted lol. That I did, and I found out that these folders will have to be searched and deleted in your cstrike folder:
http://i1021.photobucket.com/albums/af337/DigitalDead/roccat1.jpg
http://i1021.photobucket.com/albums/af337/DigitalDead/roccat2.jpg
http://i1021.photobucket.com/albums/af337/DigitalDead/roccatcfg.jpg
Its quite extensive, but you also have to check your materials, resource, roccat, and scripts folders:
http://i1021.photobucket.com/albums/af337/DigitalDead/roccatmaterials.jpg
http://i1021.photobucket.com/albums/af337/DigitalDead/roccatresource.jpg
http://i1021.photobucket.com/albums/af337/DigitalDead/roccatscripts.jpg
I also found a uninstall program, but it didn't work lol. Wouldn't matter so much to you, since you reinstalled css (the uninstall wouldn't be there).
Well I hope this helps, and if not, just PM me and I'll help out further. If this isn't the GUI you were trying to remove, well then I wasted my time (but I enjoyed it

)