You know where to find the most important files on your PC - the documents, the pictures, the music - and they're always available when you need them. So it's easy to assume that's the way it will always be.

The reality can be very different, though. Maybe you're not paying attention for a moment and delete something accidentally, perhaps there's a software bug, or something happens to corrupt your hard drive: whatever it is, the end result is that you've lost files, folders, maybe even an entire partition of valuable data.

Don't panic, though - there's a good chance that your files are still intact, somewhere on the disc. And if you act quickly then you may be able to recover everything. All you'll need is reliable free undelete software to run a scan, and we've found ten free tools which can help.

Read on for our pick of the best free undelete software...

1. Recuva Free

http://www.techradar.com/downloads/recuva

Conveniently available in a portable version, Recuva Free is very easy to use. A wizard asks you what type of files you're looking for, and where to search, then scans your system at speed (FAT, exFAT and NTFS file systems are supported).

Any files found are listed (with previews for images), and you can restore anything you need in a couple of clicks.

Recuva

Running the program in Advanced Mode provides more options, though, like a Deep Scan (much slower, but recovers more files), the ability to locate files containing particular text, and even an option to securely wipe files containing sensitive information, ensuring that no-one else will be able to undelete them.

Whatever mode you're using, Recuva is an excellent recovery tool, effective and very easy to use.

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2. Undelete 360

Download Undelete 360

Undelete 360 is the free version of a commercial product, and so leaves out some useful features (file filtering, previews and so on). These still appear in the interface, though, and suggest you upgrade if you ever click on them, which can be annoying.

Undelete 360

There are no restrictions on the amount or size of the files you can recover, though, and otherwise the program is very simple to use: point it at a drive, it'll scan for deleted files, then you can view particular file types (JPGs, PDFs, videos and more) by choosing them from a tree.

Scanning speed isn't great, but Undelete 360 can recover files that other programs miss , and so it's definitely worth considering.

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3. MiniTool Partition Recovery

Download MiniTool Partition Recovery

Standard undelete programs are perfect for recovering a few files, but if you've lost an entire partition then you'll probably benefit from a specialist application like MiniTool Partition Recovery.

The free (for personal use) program has a wizard-based interface which makes it very straightforward to use.

MiniTool Partition Recovery

Point MiniTool Partition Recovery at the problem drive, specify the area to be searched, and it'll scan for the missing partition.

A report will let you know what the program has found, and you can recover the partition in a few seconds.

You don't get a bootable recovery disc here, so if your system partition is damaged then MiniTool Partition Recovery won't help you very much.

Otherwise, though, it provides a quick and easy way to locate and restore lost partitions.

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4. Wise Data Recovery

Download Wise Data Recovery

It's hard to imagine how any undelete tool could be simpler than Wise Data Recovery.

There are no menus, no complicated options or dialog boxes: all you do is choose a drive, click Scan, and wait as the program locates any deleted files.

Select what you need, click Recover, and that's just about it.

Wise Data Recovery

Wise Data Recovery doesn't seem to work with FAT-based drives, though, recovering nothing from our test USB drive. It's only free for personal use, too. But if you just need something quick and easy to recover files from NTFS drives then it should probably be on your shortlist.