SEATTLE – A day after Microsoft announced availability of Windows Vista Beta 2, the first testers are overcoming download bottlenecks and obtaining bits. While many are finding the latest build to be more stable and better performing, they also are still hitting driver and application compatibility issues, among other system problems.

Microsoft announced on May 23 that it was making Vista Beta 2, Longhorn Server Beta 2 and Office 2007 Beta 2 available to testers immediately. Microsoft is making Vista available to its existing beta testing community first, by providing attendees of the Windows Hardware Engineering (WinHEC) conference here with DVD versions of the new test builds on May 24, and allowing other TechNet, Connect and Microsoft Developer Network subscribers to download the bits this week. Microsoft is planning to broaden the Beta 2 pools in the next few weeks, allowing up to two million testers to get their hands on the Vista test code.

Testers trying to download the Vista Beta 2 bits from Connect and MSDN reported huge bottlenecks, resulting in lengthy waits. But once they got their hands on code, testers immediately began pounding on it.

Some testers contacted by Microsoft Watch said they were dismayed that they were still experiencing driver and compatibility issues with Beta 2.

Although he was disappointed that he could not find Creative Labs' Soundblaster X-Fi drives for Vista, Carlos Echenique, Site Owner and Editor-in-Chief of the Miami, Fla.-based PlanetX64/PlanetAMD64 Windows community sites, found the new build to be "a bit more stable than the previous build and the install process is way more informative."

But one tester's "informative" is another's "excessive." Several Vista Beta 2 testers said they still are finding the number of Vista prompts requiring confirmation for specific tasks to be annoying and overkill.

Vista's User Account Control feature, which aims to improve security by running PCs in less-privileged, non-administrative mode, triggers many of these prompts.

"The newer (Vista) builds are much improved," in terms of reducing the number of prompts, said August Wilson, director of product management with Microsoft's security team.

Microsoft has developed fixes for 100 applications so they work without prompting, Wilson said, including some of Microsoft's own apps and features.

Speaking of security, some Vista Beta 2 testers said they still encountering compatibility problems between Vista and third-party antivirus products from Symantec and other vendors. Microsoft also is aware of this problem, said Stella Chernyak, a Microsoft group product manager with the Vista team.

"We are working with all the antivirus vendors to make sure all their applications will be working with Vista Beta 2 within the next 90 days," said Chernyak.

"One of the top concerns users have is application compatibility. They have hundreds and thousands of apps. We are testing hundreds of applications with each daily build of Vista inside Microsoft," she said. "And there are certain areas we are watching closely," such as the impact of the User Account Control feature on app compatibility, Chernyak added.

Microsoft announced at WinHEC a new beta of its Application Compatibility Tookit for Vista. Rather than releasing the toolkit months after shipping the final version of Vista -- the way it did for Windows XP – Microsoft is introducing betas of the toolkit now so that users can check their applications for Vista compatibility now, Chernyak said.

Testers are encountering other random Vista Beta 2 problems, as well.

Vista, especially when running the souped-up Aero user interface, eats up battery life, said Robert McLaws, a Windows tester and president of Interscape Technologies, based in Denver, Colo. McLaws said his battery lasts only 90 minutes when running Vista Beta 2.

Vista Beta 2 also is making McLaws' Toshiba laptop run red-hot, he said – way too hot to sit on anyone's lap. McLaws attributed the problem to the Windows Device Driver Model, which "draws" the desktop using a graphics card, not software. Current-day laptops weren't designed to have the graphics processor used so constantly, McLaws said.

"Most of them are designed to take heat away from the CPU (central processing unit) only, meaning the GPU (graphics processing unit) is improperly cooled," McLaws explained.

Limitations aside, McLaws said he is upbeat about performance and Tablet PC support improvements in the new beta.

Microsoft officials said at WinHEC that the company is planning to release more Community Technology Preview (CTP) and release candidate test builds before releasing the final Vista code to manufacturing. At the show, officials said Microsoft is on track to hit the new delivery targets it outlined in March, with final code due to hit in the late summer or early fall, and availability of the final Vista product to volume-license enterprise customers in November. The official launch of Vista and Office 2007 is still on for January, 2007, officials said.

But Microsoft CEO Steve Ballmer did introduce a seed of doubt in the mind of some company watchers this week, when he said that there was still a chance that Microsoft might push back the Vista launch, if feedback from Windows Vista Beta 2 indicates the product needs more work than expected.