i installed libxml2-2.9.0 and libxslt-1.1.27 then yum is broken any yum command that i ran i got the result of :

There was a problem importing one of the Python modules
required to run yum. The error leading to this problem was:

   No module named yum

Please install a package which provides this module, or
verify that the module is installed correctly.

It's possible that the above module doesn't match the
current version of Python, which is:
2.4.3 (#1, Jan 21 2009, 01:11:33) 
[GCC 4.1.2 20071124 (Red Hat 4.1.2-42)]

If you cannot solve this problem yourself, please go to 
the yum faq at:
  http://yum.baseurl.org/wiki/Faq

then i thought python version is way too old and install python 2.7.3 and install it from scratch, after some wrong trials it got worse and worse, now when i run 'python -V' i got version 'Python 2.7.3', when i run '/usr/bin/python -V', it returned 'python-2.4.3-24.el5', and no matter what i did the yum is still broken with that message. how can i get yum back? my os is: linux 2.6.18-164.11.1.el5 x86_64 GNU/Linux