Application compatibility updates, as such, are nothing new. Microsoft has rolled out several for Windows XP, and, with the December 2007 Windows Vista Application Compatibility Update (I know, it's February 2008) release this week, it has now released three for Windows Vista. The new one (KB943302) replaces the July 2007 edition (KB935280), which in turn replaced the March 2007 edition.
What's Different This Time
The March 2007 and July 2007 editions improved application compatibility with lots of recent software from major and minor vendors alike (see the July 2007 listing for details). As usual, the latest edition includes all of the previous fixes, meaning that it's much less likely that you'll need to fiddle around with the Program Compatibility Wizard or the Compatibility tab to make a legacy program run correctly.
However, this time, the update spells out another way of dealing with programs that aren't working right. In addition to improving compatibility for specified programs, this new update specifically identifies applications that will be blocked when you try to run them.
Why Block My Favorite Program?
Applications that are blocked can cause serious problems for Vista when they run. There are two types of blocks that Vista can perform:
- Hard blocks
- Soft blocks
A Hard Block prevents the software from running, while a Soft Block displays a warning that the program has "known compatibility issues."
A Hard Block is used when running a program would cause Windows Vista to become unusable and unrecoverable (think 'blue screen of death,') and a Soft Block displays a warning that the application has compatibility problems, such as system crashes, data loss, or major functionality.
Blocks are used by the Windows Vista installer when you update Windows XP on a system containing incompatible programs, and by the Program Compatibility Assistant when you try to install pre-Vista applications that aren't Vista-friendly.
What's different this time is that the latest application compatibility update adds additional programs to the database of known-problem software already present in Windows Vista's Program Compatibility Assistant. To learn more about hard and soft blocks, and to see a typical Program Compatibility Assistant soft block dialog, see the Triggering Program Compatibility Assistant for New Software page.
So, Who's On The Naughty List?
The "bad software" soft block list in the December '07 update includes:
• Adobe Acrobat Reader versions 7.0 through 7.07
• WinAntivirus Pro 2007 v5.0.356
The "really bad software" hard block list includes:
• Webroot Software Spy Sweeper 5.0
• Omniquad Total Security 220.127.116.11
And, How Did They Get on the 'Naughty List?' (Revised)
Just in case you think the folks at Redmond are picking on your favorite software, keep this in mind: applications get on the block list in two ways: Microsoft can determine the application needs to be blocked (the most likely reason that WinAntivirus Pro 5.0.0356 is on the list - it is actually spyware, as the comment below states), or software vendors can request the block when they determine that there are consistent problems with their programs under Vista. but Microsoft doesn't decide which applications need to be blocked. Surprised? Actually, softwarevendors request the block when they determine that there are consistent problems with their programs under Vista.
For a block requested by a software vendor to be approved, a software vendor must provide evidence to Microsoft (including software to test) that their software doesn't work correctly. And, because application vendors decide when their software needs to be blocked (see The Program Compatibility Assistant, Part Two posting at the Ask the Performance Team blog for an example), application vendors can also provide a solution. For example, if you're a Webroot user, the notes for the new application update tell you to install the February 5, 2008 update and all will be well with Vista.
How You Can Help Fix Problems with Legacy (pre-Vista) Programs
If you can't install (or run) your favorite pre-Vista program, don't just fume about it. Make sure you use the Control Panel Problem Reports and Solutions utility to submit system problems to Microsoft (if you don't use the default automatic reporting setting). Also, if your favorite pre-Vista program isn't working correctly, check for updates. If you can't find updates, complain to your program vendor.
And One More Thing...
The other program fix on the new compatibility update? Windows Internet Explorer 7 – "Updated to improve functionality."