(CNN) -- Computer insiders who have gotten sneak peeks at Microsoft's Windows 98 find it's an evolution for operating systems -- but not a revolutionary new product.

The most noticeable change in the operating system is that it looks like a Web browser, so that moving around a computer screen feels like moving around the Internet.

"It's best point is that it looks simpler and easier on the eyes ... less confusing to use," said Cathy Baskin of PC World Magazine.

The look isn't the only difference. There are as many as 3,000 changes in Windows 98 from Windows 95 -- most of which are invisible.

Some functional changes, however, are apparent. The computer users who previewed the operating system found their machines ran a little faster, crashed less often and offered improved sound.

In addition, commercialism is built in to the software. A list of so-called favorite Internet destinations called "Active Channels" appears on every screen.

"Companies are paying Microsoft to display advertising directly on people's desktops," said syndicated columnist Larry Magid.

The new software also is designed to make it easier to hook up extra equipment, such as DVD drives that can play motion pictures and high-definition video games.

But, for Magid, the changes in Windows 98 are not worth the $109 retail price.

"I don't see a hundred dollars worth of improvement in my computer system," he said. "I think it should have been Windows 97 or Windows 95.5."

As the reviews come in, it is not clear if the operating system will debut as scheduled.

A day after an embarrassing crash of Windows 98 at a public demonstration, Microsoft chairman Bill Gates declined to say Tuesday if it will ship as scheduled on June 25.

"The key thing is to get feedback ... making sure of everything," Gates said at the BaanWorld 98 conference in Denver.

When asked specifically about the June date, Gates would only say, "It looks like we're very close -- within a few months."

Gates said Microsoft had not given a specific release date, when in fact the software giant issued a news release on April 15 announcing that the successor to the hugely popular Windows 95 would be available in stores on June 25.

On Monday, as Gates kicked off a publicity campaign for Windows 98 with a speech at the huge Comdex convention in Chicago, the system crashed during a demonstration.

Gates tried to make light of the embarrassment, saying, "While we're all very dependent on technology, it doesn't always work."

San Francisco Bureau Chief Greg Lefevre and Reuters contributed to this report.