Windows 10 will be available from 29 July but it has been revealed that most consumers will not actually get the update that day.
Microsoft has confirmed its roll out plans and it will be phasing the release of the software in order to prevent servers being overloaded on day one and therefore making the process laborious and time consuming.
In fact, it is likely to only allow Windows Insider programme members to download the software initially, with the average consumer expected to wait until the next day or even longer.
Those who reserved the update will be next in line, but as that amounts to millions of users, even they will be served the update in waves. Each wave will scale up after 29 July but the overall roll out is expected to take several days.
If you wish to get it as close to launch day as possible, you will still need to reserve your upgrade - a process we've explained here.
Windows 10 will be a completely free upgrade for all users with computers or tablets running Windows 7 or 8.1.
The Windows Phone version of the software will be available at a later date, which is yet to be revealed and could still be months away.