Security best practise would suggest you should not use an account with admin rights for day to day work.  This would apply to home machines as well as business.

As for business networks then software installation should be done via GP, SMS or such like and use elevated installation rights.  An end user should not be installing software on a company network anyway.

If an end user requires "certain" right's then they should be delegated in active directory for that user or group.  No user, including administrators should be using accounts with full admin rights.  Full admin accounts should only be used when required for that purpose.

I remember reading in FYI mag a while back about some gent being so pleased that his account was a member of the schema admins.  He was told he should only be in that group whilst performing the task required (I think he was domain preping for exchange or something).

Thats my $0.05