Am trying to do a software inventory, is there anything other than the current operating system in use, MS office and outlook that i should list too?
Is this a software inventory or a licensing audit? Presumably you should check all of the software installed on the PC? Start -> Control Panel -> Add of Remove Programs will give you a list of packages which have been installed through the normal Windows mechanisms although there could be others that bypass this. There are management tools to assist with this sort of inventory/audit but they may or may not be relevant depending on the size of the organisation etc.
Windows has a Licensing Manager tool built in that is supposed to check license usage for various Microsoft client/server applications/services (e.g. Windows Server Client Access License (CAL) checking, Microsoft Exchange CAL checking etc.) but it never worked for me and always incorrectly told us that our licenses had been exhausted. Note also that what is required in terms of licensing is not always obvious (e.g. to have three client PCs authenticating with Windows Server and connecting Outlook (not Outlook Express) to Exchange Server requires (a) three Windows (e.g. XP) workstation licenses (b) three Windows Server CALs (c) three Outlook licenses (c) three Exchange CALs and (d) one Windows Server license.
Of course Microsoft may, unilaterally or by invitation, offer to "help" you with this sort of license auditing especially if your license purchase patterns don't match some sort of "normal" profiles that they maintain and they automatically suspect you of stealing their software. :rolleyes
Good luck! :|