my os is red hat 7.3.I download gtk+2.0.6.tar.gz and use the following command: 
tar -xzvf gtk+2.0.6.tar.gz 
//goto gtk+2.0.6 
./configure 
an error occured: my pkgconfig and glib are too old 
so I download them and use the following command: 
tar -xzvf ~ 
./configure 
make 
make install 
everything seems ok,but when i use the command : 
rpm -q pkgconfig 
I find it didn't upgrade ,the version didn't change.The same with glib. 
I wander if I had left something undone.I am very appreciated if you can tell me the answer.