Last week Microsoft released the Windows 10 update to Surface Book and Surface Pro 4, but the device owners are not happy as it failed to fix the bugs which are affecting the performance of the devices.

The January firmware update, which the company claims fixes many issues like improving battery charging, thermal tuning, wireless and Bluetooth performance, has failed to patch the nagging battery draining bug that was first noticed in October last year.

Owners complained that their Surface series devices used to be in the active mode despite putting them on the Sleep mode, thus draining the battery unabated. Some people have also claimed that Surface Pro 4 lasts only for around 3.5 hours, even though the company says the tablet can last for up to 12 hours under moderate usage.

"Bought it (Surface Pro 4) two days ago and so far the longest it has lasted on a single charge is roughly 3.5 hours. As in less than 40% of the advertised battery life just browsing the internet and using OneNote. What the hell. Anyway, I exchanged it about an hour ago. It's sitting here on my desk downloading all of the updates, but even this new one has gone through 7% in battery in about 12 minutes... on "Battery Saver" and 25% screen brightness," said a user who goes by the moniker –' radicalnegative1' – on Reddit forum.

Taking cognisance of the issue, the company has formally acknowledged the presence of the battery draining bug and promised to soon release the software patch. Until then, owners of the devices are advised to log into Microsoft customer support pages (HERE & HERE) to get help from the company staff.

"Our engineering team published some updates for Surface Book and Surface Pro 4. These updates offer refinements to improve battery charging and thermal tuning, wireless and Bluetooth performance, and to the detach-reattach experience on Surface Book. We know some of you are still experiencing issues, including issues related to power management, and we are working to address those as quickly as possible. We'll publish additional updates as soon as they are ready. In the meantime, the Surface customer forums and the Surface support site remain the best resources if you have questions about your Surface," said Jerry [MSFT], Microsoft support page moderator.

Word on the street is that this battery draining problem is due to a glitch in Intel's Skylake CPU, but there is no official word on this from Microsoft yet.

Stay tuned for more updates.