Local PHP installation conflict

Hi, I have been running my site successfully on a remote server for sometime now. However I have just installed PHP, MySQL and Apache on my local Windows XP Pro machine and when I try to log on to my site I get the following errors: Warning: session_start(): open(/tmp\sess_3bfb39a88b7b180b859aa17f1661031b, O_RDWR) failed: No such file or directory (2) in c:\program files\apache group\apache\htdocs\mysite\authenticate_user.php on line 13 Warning: session_start(): Cannot send session cookie - headers already sent by (output started at c:\program files\apache group\apache\htdocs\ncdt\authenticate_user.php:13) in c:\program files\apache group\apache\htdocs\mysite\authenticate_user.php on line 13 Warning: session_start(): Cannot send session cache limiter - headers already sent (output started at c:\program files\apache group\apache\htdocs\ncdt\authenticate_user.php:13) in c:\program files\apache group\apache\htdocs\mysite\authenticate_user.php on line 13 Warning: Unknown(): Your script possibly relies on a session side-effect which existed until PHP 4.2.3. Please be advised that the session extension does not consider global variables as a source of data, unless register_globals is enabled. You can disable this functionality and this warning by setting session.bug_compat_42 or session.bug_compat_warn to off, respectively. in Unknown on line 0 Warning: Unknown(): open(/tmp\sess_3bfb39a88b7b180b859aa17f1661031b, O_RDWR) failed: No such file or directory (2) in Unknown on line 0 Warning: Unknown(): Failed to write session data (files). Please verify that the current setting of session.save_path is correct (/tmp) in Unknown on line 0 Is this because I am running different versions of PHP? Thanks for your help