[sql-server] Counting no of rows returned by a select query

I need to count the no of rows which is returned by the following query.

select m.Company_id
from Monitor as m
    inner join Monitor_Request as mr on mr.Company_ID=m.Company_id
    group by m.Company_id
    having COUNT(m.Monitor_id)>=5

I have tried with following

select COUNT(*) from
(
select m.Company_id
from Monitor as m
    inner join Monitor_Request as mr on mr.Company_ID=m.Company_id
    group by m.Company_id
    having COUNT(m.Monitor_id)>=5)  

It gives an error message in query analyzer which says the following:

Msg 102, Level 15, State 1, Line 7 Incorrect syntax near ')'.

The syntax error is just due to a missing alias for the subquery:

select COUNT(*) from
(
select m.Company_id
from Monitor as m
    inner join Monitor_Request as mr on mr.Company_ID=m.Company_id
    group by m.Company_id
    having COUNT(m.Monitor_id)>=5)  mySubQuery  /* Alias */

Try wrapping your entire select in brackets, then running a count(*) on that

select count(*)
from
(
   select m.id
   from Monitor as m 
    inner join Monitor_Request as mr 
       on mr.Company_ID=m.Company_id   group by m.Company_id
    having COUNT(m.Monitor_id)>=5
) myNewTable

select COUNT(*)
from Monitor as m
    inner join Monitor_Request as mr on mr.Company_ID=m.Company_id
    group by m.Company_id
    having COUNT(m.Monitor_id)>=5