Monitoring server up and down status
It depends on why this server is important for you? If this server represents your web site, use URL test to check your HTTP server. If this server is mail server, use SMTP and POP3 tests. If this server is important because its running your SQL server, use some of database test or ODBC Query test. If its just file server, you can use UNC test to check free space on hard drive. I can continue this list but only you can answer to your question.
Regards
Alex
Regards
Alex