Buffer cache hit ratio

Hi all
i am new to this forum, though i am not a SQL DBA, i am responsible for monitoring the SQL instances in our company, we use windows perfmon tool
we are collecting performance data using basic SQL counters to monitor the SQL servers (instances). One of the counter is Buffer cache hit ratio. We have set the thershold for this counter is <90. this counter trigger's whenever the value gets below 90.
The problem is we are getting the alert through perfmon for one of our server (instance) for this counter value is 0. So we asked DBA to see the activity/performance of this instance. there are 5 to 6 users using this server. only one instance is there on that server. she is telling there is no performance problem on this server. then why this counter generate value as 0 continusly.
Please give me the heads up on this........
ananth

Hi thanks for your reply
its Win 2K3 with SP1 and SQL 2005 with SP2 (32 Bit)
yes it is one server with one instance
it have 4 Gb of Ram and the page file is proper
so am wondering why the counter triggers contiously zero
please help me
reg
ananth

There could be 2 things. First, the service "Remote Registry" on the server must be running. Check it. If it's running, restart it. In my case restarting helped. Secondly, as long as your server is 2005 check if service "SQL Server Browser" on the box is running.