apache+php4+extension(MSSQL) problems

Hi! I just installed the php4.04pl1+apache on win98. I have to manage an MSSQL server through it. It works just well until I use MySQL, but when I uncomment the proper extension it all fails. Not even the simple ( phpinfo() ) works. On startup I get the message unable to load php_mssql70.dll. It is there where it searches , but all I get is errors. I tried to uncomment other extension, they don't work either! Please help me on solving my problem. Thanks, MAXXxxx