Win 9x - Lost clusters explained

A lost cluster (which is also known as a lost file fragment) appears to Windows as in use, but it does not have a file associated with it. Programs such as ScanDisk and Norton Disk Doctor find and fix lost clusters.

What causes lost clusters? Crashes, mostly - by Windows and by applications. If a program crashes while it is creating, copying, or enlarging a file, some of the file's clusters may not be re-marked as available, even though the file with which the clusters are associated no longer uses or needs them. That leaves clusters marked as in use, but with no files or other clusters pointing to them.

A loose or defective drive cable can also cause lost clusters by creating bad sectors within clusters. If your system and applications don't crash often but you still end up with lost clusters, try removing your PC's case and checking the ribbon cables running between the drives and the motherboard. I know of no way a bad drive by itself could cause lost clusters, however.

In theory, you could lose clusters by defragging your drive while running other applications, although today's defraggers make that unlikely. Still, it's safer to defragment your hard drive with no other programs open.

When a disk scanner finds a lost cluster, it gives you two options: save the contents of the cluster as a file so you can look at it and decide if you need it, or mark the cluster as unused to free up wasted disk space.

The safest option is to save the contents as a file, but I have never found anything worth saving in a lost cluster, and I stopped saving them years ago. They virtually always contain extra copies of information that is safely stored elsewhere on the drive.

Join the newsletter!

Or

Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.
Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Lincoln Spector

PC World
Show Comments

Brand Post

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Aysha Strobbe

Microsoft Office 365/HP Spectre x360

Microsoft Office continues to make a student’s life that little bit easier by offering reliable, easy to use, time-saving functionality, while continuing to develop new features that further enhance what is already a formidable collection of applications

Michael Hargreaves

Microsoft Office 365/Dell XPS 15 2-in-1

I’d recommend a Dell XPS 15 2-in-1 and the new Windows 10 to anyone who needs to get serious work done (before you kick back on your couch with your favourite Netflix show.)

Maryellen Rose George

Brother PT-P750W

It’s useful for office tasks as well as pragmatic labelling of equipment and storage – just don’t get too excited and label everything in sight!

Cathy Giles

Brother MFC-L8900CDW

The Brother MFC-L8900CDW is an absolute stand out. I struggle to fault it.

Luke Hill

MSI GT75 TITAN

I need power and lots of it. As a Front End Web developer anything less just won’t cut it which is why the MSI GT75 is an outstanding laptop for me. It’s a sleek and futuristic looking, high quality, beast that has a touch of sci-fi flare about it.

Emily Tyson

MSI GE63 Raider

If you’re looking to invest in your next work horse laptop for work or home use, you can’t go wrong with the MSI GE63.

Featured Content

Product Launch Showcase

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?