Hello!
My HDD has multiple 'First allocation unit is in valid' (all windows prefech files *.pf) errors when using chkdsk.
the file system is FAT32 it is a fairly new 20GB HDD?
This same problem happened to my first drive after a power outage...
(It was a NTFS then I formatted to a FAT32)
So is it bad luck in choosing HDD's? or is it really another bad HDD? (Maybe bad RAM?)
maybe bad power supply?
Thanks!
javanoob101
It could be a bad ram, try to replace your ram, then do a chkdsk to your HDD...or HDD SELF TEST...
Hello!
My HDD has multiple 'First allocation unit is in valid' (all windows prefech files *.pf) errors when using chkdsk.
the file system is FAT32 it is a fairly new 20GB HDD?This same problem happened to my first drive after a power outage...
(It was a NTFS then I formatted to a FAT32)So is it bad luck in choosing HDD's? or is it really another bad HDD? (Maybe bad RAM?)
maybe bad power supply?
Thanks!
javanoob101
Bummer, I has happened to me, several of my clients' machines (windows XP) suffered the same issue, I tried to reformat and reuse the HDD's; BUT they came back to me.
Replace the HDD's and the problem went away.
Maybe there is something that "just goes" on them (or maybe there was a -bad- batch of some component on all these "affected" drives).
I don't know for sure, I never test to the component level on HDD's.
Let us know, what worked, when you solve this...
Topbarhive
Pick up a copy of SpinRite (I keep recommending this software but I do not get anything for my recommendation) and create bootable media (usb stick or CD) then boot off this media. Run diagnostics on the hard drive and see what it reports. hard drive controllers have error correction built in. All hard drives get errors but almost all can be corrected. That is what the controller does. SpinRite disables (temporarily) this correction so you can see exactly how your drive is performing. I always recommend running it on a new drive to get a baseline to compare to later performance. In some cases SpinRite can map out bad sectors and even recover data from those bad sectors.
Thanks for your suggestion on SpinRite but I don't really want to pay $89.00 for something I'll probably only use once....
javanoob101
I'll just ask two questions then. How much is your data worth? How much is your time worth?
Sorry for the late replies everyone...
My data is virtuallty worthless to me as all of my important data is on my USB... (All this computer is for is games really)
And I seem to have a lot of time on my hands lately...
If downloaded DataLifeGuard diagnostics (from Western Digital Corp. as my previous HDD was a Western Digital) my 'new' drive is not Western Digital but the diagnostics work fine on it. It's SMART status is all above the thresholds so nothing is failing.... The drive also does not hav any bad sectors ethier... This leads me to think that this computer itself is going bad...
Any ideas?
(if you think I need parts for this computer it is no trouble for me to get them)
javanoob101
Pick up a copy of SpinRite (I keep recommending this software but I do not get anything for my recommendation) <...>. In some cases SpinRite can map out bad sectors and even recover data from those bad sectors.
This is what I was going to recommend when I saw the thread - once you have SpinRite, you will find uses for it.
Sorry AGAIN for the late reply, My HDD doesn't have any bad sectors which leads me to think the problem is the computer components not the HDD...
I really don't want to buy spinrite because this is the only computer in the house with this problem.
any ideas?
Are their any free programs to test the mobo and/or other parts of the computer?
javanoob101
Hitachi has a free drive fitness test that you can burn to a CD and boot from. It is non-destructive so you can run it against your hard drive and not worry about overwriting your files. Download and docs are at
Thanks Reverend Jim, I'll try it out tonight.
I'll let you know what it says then we can go from there!
Thanks, javanoob101
M$'s advice when experiencing faults in the FAT [file allocation table] is to reformat that volume.
drive fitness test found no problems and this formatting doesn't really help Ive tried it on my old HDD with the same problem...
Any other ideas to what may cause this problem?
javanoob101
How about copying all of the files from the suspect disk to some other storage media then doing a low level format of the suspect disk. Normally the low level format is only done once at the factory but you may be able to get a utility for this from the manufacturer. You can start by looking here:
http://www.ariolic.com/activesmart/low-level-format.html
If you aren't ready to try that just yet then do a regular (ie non-quick) format via Windows, then do a chkdsk to see if it reports any errors.
Please not that on the site I referred you to they state that a low level format is the last step to try so I suppose I should have recommended
1) try non-quick format
2) try low-level format
in order to make the preferred choices more clear. Good luck.
I really have to start proof-reading my postings.
Hello!
My HDD has multiple 'First allocation unit is in valid' (all windows prefech files *.pf) errors when using chkdsk.
the file system is FAT32 it is a fairly new 20GB HDD?This same problem happened to my first drive after a power outage...
(It was a NTFS then I formatted to a FAT32)So is it bad luck in choosing HDD's? or is it really another bad HDD? (Maybe bad RAM?)
maybe bad power supply?
Thanks!
javanoob101
I think your HDD is facing problem.
Best Regards
JhonMoney
find the prefetch folder and delete its content ,reboot the computer .
Sorry everyone I was sick yesterday so I did not get to reply...
I'll try deleting the prefetch folder tonight after school we will see what happens.
as for a 'low level format' (you will have to explain what that means!) I would like to use that option (Any sort of formmating) as an absolute last resort
Thanks,
javanoob101
why are you using a 20gb harddrive :-)
WOW that was the fastest reply I've ever seen?!?!?!
Anyway why? because
a)It is 5Gb bigger than my previous 15Gb drive
b)My computer teacher doesn't like giving away his 80Gb hard drive all to much (he only has 3 of them)
c)Someone put the 40Gb drive in a computer in his class so I can't take it out he will get mad.
That is why I'm using a 20Gb drive--I'm too cheap to buy a bigger drive.
javanoob101
O.k just remembered, last night I ran chkdsk and it found some .log files and other file that I don't use to have 'invalid allocation units' or 'invalid size' errors I just ran Windows Update and (evidently) the WindowsUpdate.log file had an 'invalid size' error.
Like I said before, this never happened before the power outage at my house when I was camping.
Does anyone think that his is a hardware problem and not the HDD?
Thanks, javanoob101
Forgive me if some of this is too basic. I just copied it from an explanation I gave to a neighbour/friend who was unclear on the concepts as explained in highly technical (and highly inappropriate for the audience) terms to the computers for noobs evening education class.
Imagine an empty, paved parking lot with the lines painted on. There is a gate at the entrance and the parking lot attendant has a board where he keeps track of what spots are filled. At the moment the board is empty. This is equivalent to a freshly formatted hard drive. As you save stuff to disk (park cars), the attendant keeps track of which parking spots are taken. The board is equivalent to the file allocation table.
At the start, the attendant assigns parking spots in sequence so all of the cars occupy one area of the lot but as people come and go blank spots appear in the lot (your hard drive becomes fragmented). If a large semi-trailer or Winnebago shows up early enough it may be assigned several adjacent parking spots, however, if it shows up late enough in the day there may not be enough adjacent spots to be able to park. The attendant has two choices. He can refuse to park the vehicle or he can reshuffle all of the existing cars so that they occupy the lower numbered spots. This is a time-consuming operation, especially if he waits until the lot is badly fragmented. Doing this to your hard drive is called de-fragging and can likewise take a long time if you wait too long.
At some point if the attendant is having a really bad day and he just doesn't care what happens to the vehicles in the lot he just might decide to wipe the board clean and start from scratch. He doesn't actually remove the vehicles. He just clears the allocation board and pretends that the vehicles are gone. This is equivalent to a quick format. The vehicles are in a state of limbo. As long as nobody parks
Sorry. I exceeded my length limit. Here is the rest...
As long as nobody parks "over top" of an existing vehicle, that vehicle can be recovered. Likewise with a quick format. Your files are still physically on the drive and, with special tools, can be recovered.
If the attendant is feeling especially malicious he may decide to not only clear the board but also physically have all of the vehicles towed and shredded for scrap. Naturally this takes longer than just clearing the board. You will notice the same if, when you format your drive you do not check the quick-format option. Instead of just rewriting the file allocation table, the format process must rewrite each sector on the drive.
Now we get to the biggie. Suppose the owner of the parking lot has decided that the lot has just too many cracks and potholes. At that point he decides to close the lot for an extended period and send in the construction crew to rip up the lot, repave it and repaint all of the lines. This is a low-level format. Low-level formatting recreates the positions of the tracks and sectors on the drive and rewrites the control structures defining where the tracks and sectors are. Repaving the lot takes special tools. Likewise for doing a low-level format of your hard drive.
For more technical information and warnings, etc go to
There is an excellent series of pages on hard disk troubleshooting at
"I ran chkdsk and it found some .log files and other file that I don't use to have 'invalid allocation units' or 'invalid size' errors".
This is where you get to reformat that drive [partition]. These are irrecoverable errors in your MFT. Its structure has been compromised. Copy off what you wish/can, and reformat it.
I took caperjack's advice and deleted everything in the prefetch folder and the errors still persisted.
Reverend Jim, your looooong explaination helped me understand a 'low level format' the link you gave me however says not to low level format an IDE/ATA or SCSI hard disk---I have an IDE hard drive...However the link did say something about a utility to write zeros to the drive---I have a bootable floppy tool to do that!
Tonight (unlikely though) I'll try to use that tool to write zeros to my previous hard drive that had the same problem...
If I get to it tonight, I'll let you guys know what happens!!
Thanks!!!
javanoob101
"The drive also does not hav any bad sectors ethier... This leads me to think that this computer itself is going bad...". Not necessarily. It is just that the FAT structure has been corrupted, there is no way to repair that. Even deleting all files won't fix the structure. A quick or full format will create a new FAT structure.
Note, RJ, that if the parking lot is NTFS, the attendant will hold small cars in his register and not put them in the lot.. :) Strong paper.
Back to FATs...
"You will notice the same if, when you format your drive you do not check the quick-format option. Instead of just rewriting the file allocation table, the format process must rewrite each sector on the drive." No, a full format does not do that, it rebuilds the FAT and boot sector data and performs a surface scan for bad sectors.
Further, I am quite sure that it is not possible for a user to do a lowlevel format... that is manufacturer base stuff to establish the track/sector layout pattern, other disk parameters, map bad sectors and write all that into the onboard drive controller so it can manage read/writes, do the actual data management.
Writing all zeroes or any other bit pattern to java's disk won't help, that is just a security measure, it is what so-called low-level format tools do [nor will it hurt]. After any sort of format the new FAT will record any sectors and data block sizes in those sectors that it has any interest in, other bits lying there will be ignored.
I've used the zero fill utility to write zeros to my previous hard drive, and so far there are no errors or corruption! :)
I took my computer to school today where the HDD still gave errors on a working computer. Does this mean it is really bad luck in chooseing HDD's?
Also gerbil, you think I should reinstall Windows XP Home and tell setup to do a 'quick format' when it asks for which type of file system? Or should I consider using my zero fill utility (the company who made the HDD is not the same company who wrote the zero fill utility though)? Then installing Windows...
Thanks for everyone's help so far!
NOTE: I left this out earlier because I though it was il-relavent. When I got my computer I bent one of the pins so I bent it back. After, I booted it up and at the top of the screen in the centre there was ☺ (smiley face) and a @ symbol...Now there is only the @ symbol. I switch processors and the @ smybol was still there... Is the BIOS gone bad now? Is that what maybe corrupting my HDD? Would updating the BIOS fix the problem? (Dell has one more update to my BIOS)?
javanoob101
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