The Windows 10 free upgrade is available to anyone with a legit version of Windows 7, 8 and 8.1. If your system is compatible with Windows then it is most likely that you have received invitation to upgrade to the new OS (taskbar icon) for free. Quite tempting, isn't it? But if you think that Windows 10 will fix the issues that you may have encountered with your previous OS, then you should think twice as the new OS still has its own "weaknesses".
Here's a list of the issues identified so far:
Plenty of unknowns
Although Windows has been thoroughly tested in-house and by affiliated users (through the Insider Program) before being released to the public, the new OS is still prone to bugs.
A major criticism following the release of the new OS is the amount of personal info (location data, contact lists, personal details or Microsoft account) that is being collected by the Windows 10 and its apps (Cortana, Bing, MSN...). Why is your personal data being collected? How is the data being used or shared with third parties? Learn more in the Microsoft Privacy Statement.
Hardware incompatibility has always been a major issue when upgrading to a new OS, as it often represents the end of support for legacy hardware components and devices. Some drivers (audio, graphics, touchpad, webcam...) are incompatible or won't work properly with Windows 10. This phenomenon affects nearly all manufacturers:
Realtek 8111E network chipset drivers won't work with Windows 10.
AMD video cards (HD5XXX / HD6XXX / HD7XXX series) are no longer supported or not supported by the AMD driver in Windows 10.
On some laptops, the Realtek Audio Manager no longer detects headphones (when plugged in), and thus continues to play sound through the speaker.
For HP notebooks, the Conexant Audio drivers don't seem to be compatible with Windows 10.
On the Toshiba Satellite L670, it has been reported that some Fn key combos and the touchpad On/Off keys won't work after the Windows 10 update.
There's a number of software that will stop working or won't install once you have upgraded your system to Windows 10. It is the case of some legacy games (even when launched in Compatiblity Mode) and programs such as Sandra or SIW.
You have until July 2016 to get your free upgrade, so it's better to keep your current (stable) system until Microsoft, the hardware manufacturers and software companies fix the issues encountered so far with Windows 10.