Converting 8byte date to human readable format ! > Windows defender

hi,

i writing small inventory program installed software on machine ... till now, no problem. 

next part information antivirus installed, still no problem (we use mcafee on win7)...

but our new windows 8 machines, gonna use windows defender. need way check latest update of signature files... , come problem ... need convert binary value found in :

hkey_local_machine\software\microsoft\windows defender\signature updates\signatureslastupdated

to human readable value i.e. : 20130101235900 or other understandable expression.

i tried different ways no clue.  can ?

thanks

yves, beginner

[datetime]::fromfiletime([bitconverter]::toint64($signatureslastupdated,0))

Windows Server  >  Windows PowerShell