Joomla Error

[shailendra.devil79]

I An Getting An 500 Internal Server Error In Joomla 1.5 on x10:
Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request.
Please contact the server administrator, no-reply@x10hosting.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.
More information about this error may be available in the server error log.
Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

Please Help
EDIT:
I Have Reinstalled Joomla But The Problem Continues

[vv.bbcc19]

Did you change/enable search engine friendly urls?
If that is the reason..read this