Microsoft says it's fixed an issue with the Windows Phone 7 system software update that had caused some users headaches, and left others with unusable phones.

The problem first cropped up shortly after Microsoft began rolling out a phone software upgrade to ease the installation of an update it plans to release to users in the next few weeks that will add new features like copy and paste, better Marketplace search, and faster application load times. For users on Samsung phones, the installation could hang shortly after the midway point, leading Microsoft to temporarily pull the update for just those users.

"During the past week, the engineering team has pinpointed and fixed problems that were preventing a small percentage of Windows Phones from installing the February software patch," said Michael Stroh, a technology writer in Microsoft's Windows Phone 7 team on the company's Windows Phone blog. "We apologize again for the delay and continue looking for ways to improve the update process," he continued.

Stroh said the update continues to be sent out to users in waves, meaning some handsets have not yet received the notification to grab the newer software. Once they do, that process requires plugging into a PC running the Zune software, or a Mac running the Windows Phone 7 Connector tool.

Microsoft continues to urge users who may have encountered problems that left their phone incapacitated to get in touch with their mobile carrier or device manufacturer for guidance. That said, the company had originally stated that roughly 10 percent of Windows Phones had encountered problems, and not all of those were related to the same bug that affected Samsung users.