Can you please tell me how to go about obtaining the free Windows 10 for my laptop, which is currently operating on Windows 8.0? Eric  Everyone running Windows 7 or Windows 8 should get an invitation to install a free copy of Windows 10. For those running updated versions of Windows 7 SP1 or Windows 8.1 S14, this will be much the same as the offer to upgrade from Windows 8.0 to Windows 8.1. In other words, Windows Update will download the code in the background, and you will merely have to accept the offer to install it. The only limitation is that you have to install it within a year of Windows 10’s release.  If you want to make sure you get the offer, install Windows update KB3035583. This update was recommended for Windows 8 users and was optional for Windows 7 users.  If you are running Windows 7, Windows 8.0 or Windows 8.1 RTM (ie the released version, without the spring update), then you will not be able to upgrade using Windows Update. You can either update your operating system before you upgrade, or download the Windows 10 upgrade manually and create your own installation DVD using the Windows Disc Image Burner.  If you are running Windows XP or Vista, then you will be able to buy a Windows 10 upgrade: watch out for Microsoft’s usual pre-orders and special offers.  If you decide you don’t like Windows 10 for some reason, you will be able to revert to your earlier operating system.  The free upgrade is for a limited period, so what happens when I have to re-install Windows 10 (PC slow, corrupt etc)? If it’s now 18 months or two years down the line, is it now chargeable? Will there be a downloadable version I can keep to re-install? Nigel  I expect that the Windows 10 upgrade will be downloadable and will come with its own product key: this is how the current trial version of Windows 10 works. (The product key is on the Windows 10 Insider Preview ISO page.) If you have a product key then you can re-install Windows 10 in any way you want.  I also expect that Windows 10 will include the option to create your own restore DVDs. However, you might want to create these by downloading the Windows 10 upgrade from Microsoft’s website, instead of letting Windows Update do the upgrade. (Windows Update will, at some point, delete its download to save disk space.)  Once you have Windows 10 installed, it would be sensible to create restore discs, if that’s possible, or to take a drive image that you can use to restore your PC. Perhaps physical backups are not strictly necessary, but even if we never need them, they make some of us feel more secure.  I read somewhere that the free upgrade to Windows 10 will expire after one year and that the user will then have to pay for the upgrade. Is this so? Alasdair  No, that’s completely wrong. Once you have installed Windows 10 and made a note of your product key, it’s yours forever. Well, you can use it until Microsoft stops supporting it, which is usually 10 years.  I am running Windows 8.1 on a desktop PC upgraded from Windows XP via the $40 download offer. I would like to clean up my PC by installing a new hard drive and doing a new install of Windows 10. Can I get the media without paying extra for it or is there another way to accomplish this? Jim  Your $40 upgrade from Windows XP to 8.1 means that Windows Update will install Windows 10 free, or you will be able to download the upgrade separately, as explained above. You should then be able to do a clean installation on a new hard drive. The methods for marking a Windows PC as “genuine” have changed a lot since XP, but whether Windows 10 will still want to “sniff” an XP disc or make you enter your 8.1 product key remains to be seen. One would hope not, but when it comes to licensing, Microsoft isn’t always good at handling edge cases.  I’m currently running an OEM [original equipment manufacturer] copy of Windows 7 Ultimate 64-bit. Would this be eligible for an upgrade to Windows 10 too? Andrew  In theory, yes, but Microsoft has not said what it plans to do about OEM versions that were intended for small PC makers but have been purchased by consumers. It seems that most people would like their OEM version upgraded to a retail version of Windows 10, as explained on Microsoft’s User Voice website (a sort of suggestion box). This may not happen.  Microsoft hasn’t announced an Ultimate version of Windows 10, so you probably won’t get the usual like-for-like upgrade. However, Windows 10 Pro would presumably be acceptable.  When will Windows 10 be available? Abhishek  We don’t know: Microsoft has not announced a release date beyond a vague “this summer”. A few million people are now using preview versions of Windows 10, and it’s clear that it’s not yet ready for release. Bearing in mind that Microsoft will be launching Windows 10 in 111 languages in 190 countries across a wide range of devices – phones, tablets, PCs etc – then I wouldn’t expect everything to appear at once.  Late August might be a good bet for online upgrades to Windows 10 PCs, though it might be earlier or later, depending on what Microsoft includes and how many show-stopping bugs testers find in the code.  However, Windows 10 will be continuously updated, so there will no longer be a major distinction between updates (patches and fixes with KB numbers) and upgrades (features provided by installing new program code). Microsoft could therefore choose to ship a slightly incomplete Windows 10 and upgrade it via Windows Update.  It’s even harder to guess when Windows 10 might appear pre-installed on PCs in shops, but it could be another couple of months. Some suppliers might target the back-to-school market, but most if not all should have it for the Christmas shopping season. Microsoft will not want to miss that.  Have you got a question? Email it to Ask.Jack@theguardian.com
Last week’s column on Windows 10 resulted in many more readers’ questions. Here’s a handful, though nothing is certain until Microsoft launches the code