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I've just installed Win7 but I'm little confused. When booting from XP cd, there is an option to format hard drive. After choosing which partition to format, format process takes usually not less than hour (depends on size of partition), but when I clicked on Format when in Windows 7 installation interface, I received some message (I cant remember what was it, but it was not any error message or something like that) and that was it. After that I choose to install Windows 7 and installation began. "Expanding Windows Files" was the longest process of installation. Was that the part when the hard drive was formatted? I don't understand what happened? Is it possible that my hard drive was not formatted but still installation was successful?

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It's possible to install even XP on a nonformatted hard drive if you can get around that process, and if anything I'd imagine installing 7 isn't any harder. It could've used Quick Format, too, though.

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it looks like it does only Quick Format. Are all old files really deleted? I ask this because my old xp was really messed up and I'm afraid that quick format didn't do the job as full format would. Btw, I have pretty good laptop but windows 7 seems slower than XP, especially booting – ile May 26 '10 at 21:07
The files themselves are deleted, but can be recovered using special tools... if you want to be 100% sure about your drive, I would do a full format using a GParted LiveCD, then install Windows 7. You can get that here: Edit: Also, the boot time is probably related simply to the fact that Windows 7 is a more complicated OS, has more, components, etc. There are so many variable that affect this it's usually near-impossible/not worth trying to find the cause. – Suchipi May 26 '10 at 21:32
Files are not deleted in a quick format, the file allocation table is. This allows the space consumed by files to be overwritten, but until that happens, the file still exists on the disk, it is just not accessible through normal means. – MDMarra May 26 '10 at 22:15

When you use the default settings to do a clean install of Windows 7 or Vista, a completed install image is expanded onto the drive, rather than formatting and individually copying all the files. Then after the install image is expanded, the Windows configuration is modified for your hardware.

But even if you didn't use the image-based install, it's also possible the installer just did a Quick Format. One difference between a quick format and a full format is that the full format will check for bad blocks. Some recovery software can still recover your old files from both a quick- and full-formatted drive, but the files won't come back on their own.

So don't worry; however you do the installation, there is no way for your previous "really messed up" Windows XP installation to cause any problems.

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"Expanding Windows Files was the longest process of installation. Was that the part when the hard drive was formatted?"


That is my preferred method to install Vista or W7, is to skip the manual format and let setup format the drive during expanding files routine, I have had too many issues with using the format button in Vista and W7 setup, If there is a formatted partition already there, then I delete that partition first and then continue with installation without manually formatting. Deleting the partition may not be necessary due to Vista and W7 do an image install which wipes all data on the partition anyway, I just do it because of old habits.

No, you cannot install windows (XP or earlier) on an unformatted partition, you can however install it on a previously formatted partition without reformatting it but this is considered a dirty or overlay install if there is data or an old OS on the partition, not recommended

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