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MBR

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November 15, 2000 6:34:41 PM

hi, I guess this might sound daft but.......The MBR is the master boot record, does the term record mean that it records. or is the record?
Does it in turn then change after say booting a number of times. If so how can this be edited/deleted. I am wondering because after a few months the boot time of my PC changes for the worse, A clean install of all the progs normally cures this, hence it looks like something at the front end of booting.

More about : mbr

Anonymous
a b G Storage
November 16, 2000 2:53:09 PM

Don't touch you master boot record. Run scandis, it will tell you and correct errrors to the MBR using its backup copy. When scandisk and surfacescan are done do a defrag.

Take care.
November 16, 2000 4:03:10 PM

Ok, thanks thats cool, but will a format c:/sys clear the MBR? Or do I carry out a low level format?
Is this a bad thing to do, or will it be safe.
As you may gather this area is not one I'm that up on.
Ta.
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Anonymous
a b G Storage
November 16, 2000 8:56:16 PM

The MBR is something you have no need, or want, to mess with. It is a small section on the hard drive that maps out some basic areas of the drive. The problem you are seeing has nothing to do with the MBR.

There are two factors involved in the slowdown of the system over time. 1) The addition of drivers and programs, and 2) the fragmentation of the data caused by 1 and by deleteing files. Basically, files are differing sizes that can be quite large. To account for the fact that it is very doubtful to fight a file on a continous area of disk, the system will fragment the files.

When you format a drive, depending on file system and size, the disk is divided into clusters. A cluster is the smallest amount of addressable space on a hard disk. They can be small (512 bytes) with good file systems (UNIX, Verilog, etc.) or large (32k) with older file systems (FAT16 on a large drive). What happens is when the data is stored on the disk, it is split up into these clusters, and placed in any available clusters. As you delete, move, add files, some clusters get freed up in certain areas, and the filled up with other files. You will start getting files that have their clusters spread all over the place. The problem (and hence your problem you see) is that hard drives are made to be very quick when reading data in a continous area, but can be a bit slower when reading data that is scattered (fragmented).
The way to help this is a defragment program (Windows has one). There can be different settings depending on how you want the data laid out, but in essence, these programs will reorganize the data on your hard drive so that the clusters of a file are continous. That way the harddrive cache will be useful, and the system will speed up.

BTW, what keeps track of the file allocation on a hard drive is the file system table. For Windows 9x, it is the FAT (16 or 32) table. Like the MBR, this is not a table you want to mess with on your own. It is a mapping table os all the clusters on your harddisk. Messing with it will only make you lose data (unless you really know what you are doing).
Anonymous
a b G Storage
November 20, 2000 2:00:05 AM

As far as I know the MBR is contained on the first sector of the first cylinder on the hard disc. It gets reviewed straight after the POST has finished and just tells the machine where the OS is.

If you think there's a problem with the MBR then you can run a program such as Norton Antivirus because there could be a virus..or scandisk it for errors

If you wish to reset the MBR to a backup then you can use the command

FDISK /MBR

If it ain't broke don't fix it..be careful
November 20, 2000 2:41:20 AM

To clean your mbr, you have to enter the following command "fdisk /mbr" it will delete/remake your mbr!
November 20, 2000 2:47:13 AM

...but I really dont think your problem is due to that, maybe a program/driver is causing the problem. Try to defrag or if you have a NIC, check if it is not trying to get an ip adress from the network even if youre not on a network! You can also edit your "msdos.sys" file adding "BOOTDELAY=0" under "[OPTIONS]" I think. (with my win2k machine I can't verify) :)  It will reduce by 2 seconds your win9x booting time.

Hope that helps!
November 20, 2000 5:47:45 PM

Many thanks for all your help, I won't mess with the MBR till it all goes pear shaped. But at least now I'm clear on the who what where and why of it all.

Thanks
!