Microsoft Corp is offering 40% discounts to the 1.3m users of 3Com Corp’s version of LAN Manager, part of 3Com’s previously announced strategy to shift its 3+Open business to Microsoft: 3+Open customers will be offered the discount to replace their software with LAN Manager 2.0 until June 30, and a one- to five-user version will cost $600, down from $1,000; 3Com sold its 3+Open line to Microsoft, and 12% of the workforce were laid off.