This may not be in right vein, but I guess my first question is, "What version of windows are you using and how did you install the XOG client?"
I am wondering, for example, if the GEL executable is truly accessable in your C:\CA\Clarity\XOG\bin directory? Windows 7, for example wants to put your GEL executable file into c:\program files (x86)\ca\Clarity XOG\bin when installing a XOG client through the IE browser. This is because 64-bit Windows 7 IE has a built-in predeliction to install 32-bit executables there.
This is further complicated by the fact that GEL can't seem to recognize directories with parentheses in the name. There was a time not too long ago when those characters were illegal in a Windows directory name.
The work-around is to use the 8-byte directory designation for "program files (x86)". So instead of setting your directory to say "c:\program files {x86}\ca\clarity XOG\bin" you use "c:\progra~2\ca\clarity XOG\bin".
Again, I don't know if this is relevant to the specific problem you are experiencing, but this is the first suspect that comes to mind. My second suspect is content of your PATH expression, but one suspect at a time.
Good hunting.