Microsoft's first Windows Phone 7 update is apparently causing some users' phones to not work.
Microsoft has advised at least one person to take his device into a store.
Microsoft released the update on Monday but played it down. The update was designed only "to improve the software update process itself," wrote Michael Stroh on the Windows Team Blog.
"So while it might not sound exciting, it's still important because it's paving the way for all future goodie-filled updates to your phone, such as copy and paste or improved Marketplace search," Stroh wrote.
Microsoft said in a statement on Tuesday regarding the update causing phones to stop working that it is aware of the problem and "looking into these reports."
Windows Phone 7 users update their phones by using either the Zune software for Windows OSes or the Windows Phone 7 Connector for Mac using a USB cable, Stroh wrote.
Both of those programs, however, may need updating before the new update is installed, he wrote.
One user, Alex Roebuck, wrote on Twitter that the update had "bricked" -- the term for when a mobile phone is unusable -- his Samsung Omnia 7.
"We're very sorry for the inconvenience," Microsoft responded on its support Twitter feed. "For this issue we would suggest taking it to a store."