I also noticed the recent availability for download from the windows update site this 'new' May version of Windows Installer 3.1, which first appeared in the windows update critical downloads list last Month in an April version.  I have manually downloaded and installed this month's current version, as well as last month's version,  both with no apparent problems.  Does any Microsoft expert on the forum with insight into Windows XP Pro have any more info on the function of this Windows Installer 3.1 download?  Thanks again for your help.