Monthly Archive


Monthly Archives: November 2014


The ability to create transcripts of your PowerShell activity is great for keeping track of what you’ve done. They are also very useful when testing as you can keep a record of your results. 


There’s one problem though – transcripts don’t work in the ISE.  Try this in PowerShell 4.0 or earlier:

Start-Transcript -Path C:\Temp\tran1.txt


You’ll get an error like this:

Start-Transcript : This host does not support transcription.
At line:1 char:1
+ Start-Transcript -Path C:\Temp\tran1.txt
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotImplemented: (:) [Start-Transcript], PSNotSup
    + FullyQualifiedErrorId : NotSupported,Microsoft.PowerShell.Commands.Start


Your script will run then you’ll get another error:

Stop-Transcript : This host does not support transcription.
At line:3 char:1
+ Stop-Transcript
+ ~~~~~~~~~~~~~~~
    + CategoryInfo          : NotImplemented: (:) [Stop-Transcript], PSNotSupp
    + FullyQualifiedErrorId : NotSupported,Microsoft.PowerShell.Commands.StopT


Now try the same in PowerShell 5.0 and you’ll get this:

Transcript started, output file is C:\Temp\tran1.txt


Your script will run and you’ll see this at the end:

Transcript stopped, output file is C:\Temp\tran1.txt


Your transcript file will will be created and contain the desired output.


Another useful addition to your PowerShell tool kit – transcripts now work in ISE

PowerShell classes – – static classes

A static class is one that you don’t need to create  an instance of the object to use – the [math] class provides many examples e.g.

£> [math]::pi


You can create a class with static methods using PowerShell classes:

class stest {

static [int] doubleup ([int] $in){

return $in * 2



Its used like this:

£> [stest]::doubleup(2)


Where could you use this – possibly to resolve look up values for instance when decoding WMI integer values or if you have a series of calculations you’ll be using in several select statements

WMI integer properties – alternative decoding options


WMI has many properties where the the value is an integer:

£> Get-CimInstance -ClassName Win32_LogicalDisk | Format-Table DeviceId, DriveType, Size, FreeSpace -a

DeviceId DriveType         Size    FreeSpace
-------- ---------         ----    ---------
C:               3 135810510848 120492625920
D:               5


In the example drive type 3 is a standard hard disk and drive type 5 is defined as a compact disk



Remembering these can be a pain – there are a couple of ways to decode these values.


You could use a hash table – I showed many examples of this in PowerShell and WMI –


$dtype = DATA {ConvertFRom-StringData -StringData @'
3 = Hard Drive
5 = Compact Disk
Get-CimInstance -ClassName Win32_LogicalDisk |
Format-Table DeviceId, DriveTYpe, @{N='TYpe'; E={$dtype["$($_.DriveType)"]}}, Size, FreeSpace –a



DeviceId DriveTYpe TYpe                 Size    FreeSpace
-------- --------- ----                 ----    ---------
C:               3 Hard Drive   135810510848 120495980544
D:               5 Compact Disk



Define the hash table via ConvertFrom-StringData . You can then just use the hash table as a look up to convert the numeric value of drive type into a descriptive name.

With WMF 5.0 and PowerShell classes there is another option


enum dtype {
HardDrive = 3
CompactDisk = 5

Get-CimInstance -ClassName Win32_LogicalDisk |
Format-Table DeviceId, DriveTYpe, @{N='TYpe'; E={[dtype]$($_.DriveType)}}, Size, FreeSpace –a


DeviceId DriveTYpe        TYpe         Size    FreeSpace
-------- ---------        ----         ----    ---------
C:               3   HardDrive 135810510848 120496607232
D:               5 CompactDisk


Create a enumeration using the enum keyword. The descriptive text CANNOT have spaces (delimited strings don’t work either). You can then substitute the enum value into your calculated field.