When i see jar file missing, i normally 1)check the Java_home settings. It might be different. 2) Then do a search for the jar files, copy them to an accessible location (like JAVA_HOME\ or BIN\ or to the folder, where the application's executable is present) 3) Check for Java versions (in 4.5, we need to keep SP and Web Console separate) 4) Path settings for Web Server 5) Re-install !!!
I am dam sure you have tried all these, still i couldn't resisting posting a reply for you, since you have helped me a lot !!!