I am puzzled by your employers deciding not to update this.
1] Bad for business. If the whole of the US is now on one DST and your business is on another, there's going to be some conflicts there. Perhaps not noticeable at first, but the effects could be cumulative.
2] If those business XP systems are already up to date with Service Pack 2, (SP2), then this update will already have been issued in a Windows Update.
I would update.