How Can I Count the Number of Computers in a Domain?

ScriptingGuy1

Hey, Scripting Guy! How can I count the number of computers in a domain?

— TN

Hey, TN. Here’s a true story for you. About 5 years ago, when one of the Scripting Guys first started at Microsoft, his group here (which might not be the most technically-savvy group at the company) needed to get a count of all our computers. How did they do that? Why, exactly the way you’d think they would: they distributed floppy disks to everyone. On that floppy disk was a batch file that would grab the computer name and write it to the disk. Everyone was instructed to place the disk in the floppy drive of each of their machines and then run the batch file. Later that week, IT types came around, collected all the disks, and – presumably – collated all the information to get their computer count.

Like we said, ours might not be the most technically-savvy group here. Or anywhere, for that matter.

Admittedly, that’s a tough act to follow. And while we can’t claim to have come up with anything as creative as distributing floppy disks to all your users, the following script – as humble and unimaginative as it might seem – will nonetheless give you a count of all the computers (or, at least, all the computer accounts) in your domain:

On Error Resume Next

Const ADS_SCOPE_SUBTREE = 2
Set objConnection = CreateObject(“ADODB.Connection”)
Set objCommand =   CreateObject(“ADODB.Command”)
objConnection.Provider = “ADsDSOObject”
objConnection.Open “Active Directory Provider”
Set objCommand.ActiveConnection = objConnection
objCommand.Properties(“Page Size”) = 1000
objCommand.Properties(“Searchscope”) = ADS_SCOPE_SUBTREE 
objCommand.CommandText = _
    “SELECT Name FROM ‘LDAP://dc=fabrikam,dc=com’ WHERE objectCategory=’computer'”  
Set objRecordSet = objCommand.Execute
Wscript.Echo objRecordSet.RecordCount

What’s that? Why, yes, this is a script that does a search of Active Directory. And, yes, that does mean that we won’t explain the details of the script today; instead we’ll refer you to the two-part Tales from the Script series Dude, Where’s My Printer? if you need some background information on searching Active Directory. And, yes, that also means that – say, wait a second: who’s writing this column anyway?

As you were probably about to point out, while this is an Active Directory search script it’s actually a bit simpler than most such scripts. For example, our SQL command is pretty bare-bones: we simply write a query that returns a collection of all the objects that have an objectCategory equal to computer:

objCommand.CommandText = _
    “SELECT Name FROM ‘LDAP://dc=fabrikam,dc=com’ WHERE objectCategory=’computer'”

After defining the query we call the Execute method, which returns a recordset consisting of all the computer accounts found in the domain. At this point we would normally set up a Do Loop to walk through all the items in the collection (that is, all the computers in the domain) and echo back whatever properties we specified in our query. For this script, however, we don’t have to bother with any of that. Why not? Well, all we wanted was a count of the number of computers. As it turns out, ADO (ActiveX Data Objects) recordsets all have a property named RecordCount that tells you how many items are in the collection. Want to know how many records are in the recordset (which – by extension – tells you how many computers are in the domain)? All you have to do is echo back the value of the RecordCount property:

Wscript.Echo objRecordSet.RecordCount

That’s it. Like we said, it’s a bit on the boring side. But it does save you a lot of money on – no, not car insurance. On floppy disks. Sheesh.

ScriptingGuy1

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