Today, after a restart, my pc opened up but it reverted to winxp, Win7 has disappeared. How do I get win7 back? I don't have an installation cd, nor a record of my key, but I imagine MSWindows has a record of my subscription? At any event, there are lots of 'free' win7 downloads available but I want to make sure the one I choose is legal. If I manage to reinstall win7 will my lost file data also reappear?
There are two types of installs
Clean install, you boot from the CD. In that case everything is lost, but it is the best type of install
Then you have an upgrade install. You boot from the OS (if you can) then install the CD and follow the directions on the screen.
Unless you purchased direct from MS, no, they don't keep a record of the Windows you have licenses to.
Perhaps there's some sort of upgrade path you can take from your XP key, or perhaps you can try searching the registry using a myriad of key finders to locate it, but otherwise, you're probably out of luck unless you can prove you do in fact have a legal Windows 7 license to MS.
It's not possible WIn7 could revert to XP, since XP cannot even be in-place upgraded to Win7. What must have happened is that Win7 was installed to another partition. Do you remember getting a Dual Boot menu to choose between the OS's?
Please take a Screenshot with Paint of XP Disk mgmt after maximizing its window, then attach it to your reply using the paper clip icon in reply box. We'll try to sort out what was done since apparently no one there knows or cared where Win7 was installed.
To reinstall you must have the Product Key but can obtain everything else needed to do a perfect Clean Reinstall Windows 7 in the blue link. This time please pay close attention to how to set up your partitions. Attention to detail pays off with the best install one can have, which you can keep that way forever if you stick with the steps and save a backup image of the finished job.
I think Greg is right, but OP may not have seen a dual boot menu. Win7 may have been set up to boot without user selection. Then when Win7 broke, the machine defaulted to the next boot menu item, XP. Pop a Win7 repair disk into the optical bay and repair the W7 install.
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