Hi,
Database gone down may have many problems, here is a few suggestions based on my experience.
maybe first you can check the database services is started(if is MS SQL, then make sure all services of SQL server is started)
Can't found admin account maybe because database is offline or damaged, maybe you should run the reset database wizard located in the start menu, this usually fix the problem but you "maybe" lose your data in the original database.
Also here is some information about cisco VPN Client 5.0.06(newest) from cisco,
http://www.cisco.com/en/US/docs/security/vpn_client/cisco_vpn_client/vpn_client5006/release/notes/vpnclient5006.html#wp63537
and I just noticed that the software doesn't support Windows 2003, so very possible that this problem is caused by it.
Hope these will help, Best Regards
Michael