Microsoft released a minor update to its mobile OS yesterday, intended to get the system ready for a larger update in March.
While Microsoft admitted the update wasn't very exciting, it has caused trouble for owners of the Samsung Omnia 7 and Focus, with users reporting the update stalls mid-way through.
Some users report the update stalls in the seventh stage of the installation, while others have said in online forums that their handset freezes when it tries to restart after the sixth stage.
"Finally lost my patience and pulled the plug," said one forum poster. "Turned it on again and no problems, just no update installed."
"Looks like I'll just unplug and restart it," said another. "I'm seriously disappointed by this, but hopefully Microsoft learns whatever it needs to learn from this."
Not everyone blamed Microsoft, with one user noting other manufacturers aren't having the same problems: "Out of eight handsets, it's the two Samsungs causing a problem."
A Microsoft spokesperson said: "We’re aware of this issue and are looking into these reports."
However, support staff have warned Samsung users to hold off installing the update.
"We would recommend at this time, not to retry the update, as subsequent attempts will fail similarly," a support moderator said on Microsoft's help forums. "While we continue to investigate the issue, we would ask that you not attempt the update until your device alerts you of another update opportunity, in approximately three days’ time."
"At this point we would suggest unplugging and sit tight while we take a look at this issue," the Windows Phone support Twitter feed advised.