I need to convert a computers active directory GUID into hex. The format I need this in is displayed the way I need it when I view the GUID through Active Directory Users and Computers, but every attempt to convert the return from [adsi] returns a different result than I get when I view the value through the application. 

All I want to do is display the following in HEX

([adsi]"LDAP://CN=SomeComputer,CN=Computers,DC=SomeDC,DC=com").objectguid

$guid = ([ADSI]'LDAP://CN=SomeComputer,CN=Computers,DC=SomeDC,DC=com').Properties['objectguid'].item(0)
$guidInHEX = [string]::Empty
$guid | % { $guidInHEX += '{0:X}' -f $_ }
$guidInHEX

• Marked as answer by Oldguard Tuesday, July 30, 2013 4:29 PM

If you would like the GUID to appear exactly as its hex equivalent appears in the Attribute Editor in ADUC, you can do the following:

$val = ([adsi]"LDAP://CN=SomeComputer,CN=Computers,DC=SomeDC,DC=com").ObjectGuid

[System.BitConverter]::ToString([byte[]]$val.Clone()).Replace('-',' ')

I'm using Clone here to get around the type casting.

This is how it's displayed in Attribute editor:

$bytes =([adsi]"LDAP://CN=SomeComputer,CN=Computers,DC=SomeDC,DC=com").objectguid

$guid = new-object guid(,$bytes[0])

There must be some different rules on the GUID syntax produced by the different methods:

My method:

71ACE0F06EA47D4395D2ACC82F57F644

Neil's method:

71 AC E0 F0 6E A4 7D 43 95 D2 AC C8 2F 57 F6 44

Piotrek82's method:

Guid                                                                                                               
----                                                                                                               
f0e0ac71-a46e-437d-95d2-acc82f57f644

Notice the hex numbers are arranged differently using System.GUID.  Perhaps I'm missing something on the format of GUID.

All three are correct.  Yours and mine are the same, I just added spaces between each byte as this is how it is displayed when you use the attribute editor in ADUC.  The System.Guid method is returning the same answer but the endianness is reversed (I believe System.Guid will always return Big endian but not 100% sure, I've only tried it on Little endian systems).

Yes I'm still confused about which one is the industry standard.

If you're trying to convert in T-SQL it's quite simple: All you gotta do is query LDAP from SQL Server and cast the objectID as a uniqueidentifier.

"CAST(objectGUID AS uniqueidentifier)" and you will convert "0x71ACE0F06EA47D4395D2ACC82F57F644" to "f0e0ac71-a46e-437d-95d2-acc82f57f644" in no time; the way it's displayed in the Attribute Editor tab in ADSI Edit.

Cheers