It is a very bad idea to call this kind of corruption "fade" or "wear out". Furthermore, what you write is so general that it's true by definition but carries virtually no information.
The sun will destroy earth in a few billion years and the universe will presumly collapse somewhen.

If you are that easy with throwing big numbers, please stay away from them. What you are doing is not arguing.

I see one way how Microsoft Windows would really incrementally corrupt the whole disk: Excessive defragmentation. If you do not use ECC RAM and most PCs don't, there's of course a chance that data is corrupt in transit.

Data in disk sectors doesn't "fade" either. Either the sector can be read or it cannot be read which causes a failure. There's no fuzzy state in-between that would justify a word like "fade". You can take it for granted that a harddisk will fail completely very soon after you notice some read or write errors. These are also hard errors, not something the OS can miss.

However, please look at the initial question resp. problem. The person complained that his computer gets very slow after some months and a fresh installation fixes this. This is a typical Windos problem which is caused by a bloated registry, disk fragmentation and dubious software running in the background which was installed as a gimmick or extra along with other software.

Suddenly the topic changes to data that seems to "wear out" or "fade". Keep in mind that he was initially also talking about a 6 months cycle. You see, there are two topics with nothing in common mixed into one.

No, it's not. The difference is that every write operation has a certain chance of failing and every day there is a certain chance, your hard drive loses information.

With the sun, there is no chance at all that it will destroy the earth in a million or a billion years. Plus, the universe won't collapse. Someday it will just stop expanding and stay that way (at least that's what recent experiments suggest).

You can even ask the company producing the harddrive how probable it is that information is lost. They usually keep very accurate statistics about that kind of errors.

I have lost more than one harddrive that way. Usually it starts with recoverable errors, e.g. the harddrive needs more than one attempt to read a single block, but once that happens the probability of losing more blocks grows very quickly and it usually doesn't really matter how old the harddrive is when that happens, - although the higher the load on the harddrive has been, the more probable it is...

Wrong, there is this fuzzy state. In a problematic block on your harddrive the data you read may change everytime you read it. It's a little complicated to explain, without going into details on how data is stored on the harddrive and what is used to read it but you can compare it to an old record that was played too many times. The sound just isn't as clear and brilliant anymore and you have to pay really a lot of attention to understand the lyrics.

Well, I_Have_No_Account

Here is a little piece of trivia for you and an experiment ONLY you might want to try. I wouldn't suggest others try this, as you will probably have to replace your hdd. Take and open up your computer so you can see your hard disk drive. Make a backup copy of your hard disk drive. You will need it! Then take a magnet and slowly move it accross your hard disk drive.

Once you have done this see if your computer can read your hard disk drive. I am almost certain it won't be able to, as your digital data is magneticaly encoded on your hard disk drive.

This gets to what CRT was asking about, and trap_jaw4 was relating to.

Yes theoretically and realisticly digital data can fade "lose it's magnetism".

Point made, do what you wish with I_Have_No_Account, ursula, provided I_Have_No_Account didn't do the experiment.

If I_Have_No_Account did do the experiment...

I hope this answered your question on how and why this might happen CRT.

If you explain that much, that's fine because it's sufficiently detailed to show that these kind of problems are not related to his 6 monthly reinstall cycle.

Ok, Fabion, you call complete lossage "fade"? You mean CRT goes through his computer with a big magnet? I doubt that.
You do understand the difference between a physical rotting media and bit rot, don't you? Are you trying to imply that I claimed the data would survive a physically damaging media?

The problem here is, that everybody agrees with anyone while any of those is actually talking and thinking about completely different things.

I_Have_No_Account

you fail to see the point whether you physically do it or it happens over time. Items that are magnetised lose there magnetism over time. This happens naturaly.

nobody reely ansered the ? a was asking : what causes windows to corrupt itself and slow down, EVEN when the drive is 75% free AND is defragmented reularley AND when the system is suposedley virus and spyware free???? PS i allsow tride using REGISTRY REPAIR and that didet do anything for my speed.


ok ? # 2 : my music and stuff is on a compleatley seperate HDD from the one windows lives on. i know there safe from windows system failures there , but are they safe from this "bit rot" (by bit rot i dont meen phisical problems with the drive like head crashes and letting a magnet/transformer etc get too close) i meen can the files simpley corrupt themselfs just from being read and from sitting there on the drive for 10-20 years?

can simpley moving the files from folder to folder on the same drive corrupt them??

and can a HDD degrade the same way older style magnetic tape can???

i read somware that it takes a magnet (nomal fridge magnet type) 20000years to lose its magnetisem. HDDs are made differantley than tapes so the magnetic particals should be more robust than that on a tape and should last much longer than a tape . so can a HDD be much more differant than a fridge magnet life span wize??? (magnetic lifespan of the data itself ,not the bearings or motor lifespan witch is obviousley less) (and of corse assuming it is not expozed to a magnetic feilds)

There are several possibilities:
- Buggy drivers
- Buggy windows
- Buggy hardware
- Buggy end-user software

I answered that:
- Disk fragmentation
- Bloated registry; this doesn't mean it's corrupt, just that it contains a vast amount of (very often unused) entries.
- Unnecessary background programs

You can only show that there's a virus, there's no tool to show that there is NO virus. Well, there's a way but it is hardly practicable.

10 years sounds reasonable for a harddisk lifetime. 20 years sounds risky. The problem is that old hardware from the 80s or even older often works fine. Most electronic problems are caused by bad capacitors and sometimes fine rifts in electronic boards. Old disks and tapes stored data less dense and the used materials were better known and understand than some of the modern materials used. Usually, old hardware and media are much more robust whereas high-end stuff is comparatively sensitive.

However, especially harddisks are highly "intelligent". So you can monitor them and most of the time replace them before they fail. This feature is called "SMART" and there are certainly tools for Windos which can use this to diagnose problems and tell you the current status of your disk. Of course, that helps with disks in-use only.

If your drive supports power management to turn the drive off when not in use, you should disable it by all means. The most critical event for a harddisk is spin-up/spin-down and stresses it the most. There's a very simple rule that applies to almost all materials: Frequent drastic temperature changes
make things brittle and thus destroy it in the end. A drive that runs 24/7 is much less stressed than one in a computer which is switched on/off several times a day.

Every write-access can (in theory) cause damage to the files due to the reasons given above and explained by others. You can detect this only by keeping checksums for every file around. For example, I always take the time to compare a burned CD with the original data on disk after I once burned some CD-RWs with a defect surface without getting any error from the burner.
I don't see any evidence that mere read-access could cause anything like that.

If you really move files from one folder to another in contrast to moving them to a different partition, coruption should be fairly unlikely as this causes only some changes in the directory entries. That's why this operation works in an instant.

In any case, it's by far more likely that you use data by viruses or accidential deletion than by "bit rot".

Certainly. A HDD contains a bazillion of very very small "magnets" only a few atoms in size. The disk might still work fine due to redundancy and/or error correcting codes even if
a good amount of those little magnets lose their magnetism or flip but sooner or later too much of them will fail and render the disk useless.

Your fridge magnet will probably still work fine with a few magnetism left.

You should check your the website of your HDD vendor. They tell you detailed specs of any model. My drive, for example, is "designed for 5 years". Incidently, as a rule of thumb, I wouldn't trust any media more than 5 years.