Sherif,
A few things to consider.
1. Did you generate a Keys.ini
2. Did you specify the path to keys.ini in NW Admin?
3. If Keys.ini is on a LINUX box, does it have the correct permissions?
4. Does the dispatcher come up in test mode?
5, Can you log into the database as mxmc_prov, mxmc_oper, and mxmc_rt? (if you installed to another schema, you'll need to use whatever it was, but the default is mxmc)
Also take a look at your overall DB configuration in the MMC. This article was written for SQL server, but you might want to look at your configuration with this info in mind (and a DBA 
)
Finally, to amplify what Christopher Leonard mentioned, did you install all elements of IDM and configure them properly (Designtime, Runtime, JMX) I don't know that you can import anything if this is not done correctly.
Regards,
Matt
