Powershell script check application versions on multiple machines. - windows

Question

Im currently running the following commands, but im running them through a foreachloop. I can currently output them both to a csv as just a list for each machine, but ideally id like to output them to a csv of all the machines in the loop, that has the apps listed along the top, then below the computername, version, etc. so that i can append the csv and just have one big csv that i can sort and filter when opened in excel.
Aditionally id also like to be able to alert if app versions are differnt than my baseline, not sure where to start on this though.
$InstalledApps = gwmi Win32Reg_AddRemovePrograms64 | Select DisplayName, Publisher, Version
$InstalledApps +=
C:\Windows\SysWOW64\WindowsPowerShell\v1.0\powershell.exe -Command {gwmi Win32Reg_AddRemovePrograms | Select DisplayName, Publisher, Version}
$InstalledApps = $InstalledApps | sort displayname | Get-Unique -AsString
$InstalledApps| Select DisplayName, Publisher, Version | ogv -PassThru | export-csv .\apps.csv
Thanks

Answer 1

Powershell v3. and above.
Try to use CimInstance instead of WMI where possible.
#Define a Table Array
$MasterTable = #()
#Define computer list
$Computerlist = "computer1", "computer22"
#Run Foreach to retrieve data from each computer remotely
Foreach ($computer in $Computerlist) {
$MasterTable += Get-CimInstance win32_product -Computername $Computer |
Select-Object #{Name = "Computername"; Expression = {$Computer}},
#{Name = "SoftwareName"; Expression = {$_.Caption}},
#{Name = "Publisher"; Expression = {$_.Vendor}},
#{Name = "Version"; Expression = {$_.Version}}
}
$MasterTable | export-csv .\apps.csv -NoTypeInformation -Append
This should give you one CSV export with four columns containing all the information you require (incl the computername Get-CimInstance was run against).
You can do some additional logic with the MasterTable Variable if you like before exporting to CSV

Answer 2

Yes, this is also possible using WMI, however I would suggest you look at migrating WMI calls to CimInstance instead using Powershell v.3 and above as WMI is legacy and is not really firewall friendly as CimInstance is for example.
But here is the code for using WMI.
#Define a Table Array
$MasterTable = #()
#Define computer list
$Computerlist = "computer1", "computer2"
#Run Foreach to retrieve data from each computer remotely
Foreach ($computer in $Computerlist) {
$MasterTable += Get-WmiObject -Class Win32_Product -Computername $Computer |
Select-Object #{Name = "Computername"; Expression = {$Computer}},
#{Name = "SoftwareName"; Expression = {$_.Caption}},
#{Name = "Publisher"; Expression = {$_.Vendor}},
#{Name = "Version"; Expression = {$_.Version}}
}
$MasterTable | export-csv c:\temp\apps.csv -NoTypeInformation -Append