What to do right now
- Back up important files now, before running long tests.
- Check whether the values change over the next days.
- If pending or uncorrectable sectors grow, plan to replace the drive.
What to do
Back up first
Copy the files you cannot lose to another disk before anything else. If copying fails on some files, create a disk image with a bad-sector-aware tool.
Record today's values
Note the reallocated, pending and uncorrectable counts. A screenshot of the health view is enough.
Check again after a few days
Stable values over weeks are less worrying. Growing values mean the surface is still degrading.
Run a read-only surface scan if needed
A surface scan shows where reads are slow or fail. Run it only after your backup, because it reads the whole drive.
Replace the drive when the trend is clear
Rising pending or uncorrectable sectors, or a surface scan with many errors, mean the drive should be retired from important use.
What each value means
Reallocated sectors (ID 5) are sectors the drive found unreliable and replaced with spare sectors. Data was moved, and the bad sector is no longer used. Current pending sectors (ID 197) are sectors that could not be read reliably and are waiting: the next successful write either fixes them or causes a reallocation. Offline uncorrectable (ID 198) and reported uncorrectable errors (ID 187) count reads that failed even after error correction.
Pending and uncorrectable sectors are the more urgent ones, because they can mean data in those sectors is currently unreadable. Large studies of drive fleets have found that drives with non-zero values in these attributes are more likely to fail, although many keep working for a long time.
Why pending sectors sometimes go back to zero
When a pending sector is overwritten and the write succeeds, the drive may clear it without reallocating. That is why values can fall. It does not undo the warning: the area was weak once. Watch the trend over weeks rather than reacting to a single reading.
What this cannot tell you
- There is no universal safe threshold; vendors set their own.
- A drive with zero bad sectors can still fail from electronic or mechanical causes.
- Data in a sector that became unreadable may be lost even if the sector is later reallocated.
How FileFix Ultimate helps
- Shows these SMART values with plain-language explanations and a clear status.
- Runs a read-only surface scan with a latency heatmap and stops when errors pile up.
- Creates bad-sector-aware images that read good areas first and return to weak ones later.
- Never writes to the drive to “fix” sectors.
FileFix Ultimate is free, works offline and never writes to the drive you are recovering from. Check the signature before you run it.
Frequently asked questions
Can I fix reallocated sectors?
No, and you do not need to: the drive already replaced them. What matters is whether more appear.
Should I run CHKDSK /r?
Not before you have a backup. It reads the whole drive and writes to it, which stresses a weak disk.
Do SSDs have reallocated sectors?
SSDs manage bad blocks internally and report them differently, often as available spare or retired blocks. The idea is similar.
Is a drive with a few reallocated sectors safe to keep?
For non-critical data it can serve for a long time, as long as the count stays stable. For important data, keep a current backup and replace it if the number grows.