Each version of windows loads a different set of files to operate the system.
Each successive version has added more, but there are some basic files.
One type of windows developed from MS-DOS and had a file system they call FAT.Windows 95
used a FAT16 type, and it required certain files, the total space need
for the files might have been a couple hundred megabytes. Windows98
used the same ones, but of course more were added. The file system became FAT32, offering more features. Windows ME
completed that particular line of development, again becoming larger in size due to new features added, but it is basically the same in many ways as the original windows OS.
When released, Windows NT
was the first to use the NTFS file system.
All required files equaled about 250 MB. Many of those same files were
used in Windows 2000
. More were added, making it need 750 MBs of space on your PC to operate. When Windows XP
was released, it shared many of the basic files of the other two, but had more to it. It needs 1,500 MBs worth of files to operate it.
Then each update adds files, so winXP SP1
is bigger, and SP2
makes it even bigger. About 24 updates are now applied the winXP Service Pack 2
, making that OS about 2,000MB of files, when fully updated, all of them are needed. For one reason or another.The exact list of files needed for exactly what in any of the systems is not published.
After many years, those that are needed for any particular service or process have been identified fairly accurately, but changes do occur each time an update is added.Your question
At this time winXP can operate a system using about 400-500 MBs of the files in has, or even less. What matters is exactly how you use the PC. Each time a set of files associated with a particular process or action are deleted, if you decide to do that, you need to know you won't need them again. If you do, then you must re-load them and place them back where they belong. Easier said then done, but perfectly possible.
It's also easy to say just leave anything that is in each of the folders that windows loads. There are three of them in winXP.
Documents & Settings, Program Files and WINDOWS.
Basically to leave them alone is good advice,
the exception being to delete any malware that puts itself in those folders.
What also needs to be understood is that from the very start you as a user
are requiring that the operating system "activate" files in those basic folders,
or "not activate". Many of the files contained are used when and if they are.
Several more are "backup" copies of ones that are "in use" depending on what
your requirements are.
Lets say you have the following hardware plugged into your motherboard:
A CD-RW drive
A Floppy drive
A Hard Disk drive
You use them all at one time or another when operating your PC.
They are not the exact same ones that someone else uses.
In fact the motherboard itself may be different.
The Windows version you use will require that certain ones of the many it has
'on-hand" will be in use, while many others are not.
They remain as files on your PC, and part of the OS however.
Any software you add becomes files in one of the windows folders, Program Files.
You may choose to place those files elsewhere, but each of the programs you add
requires that the operating system understands, and utilizes, files it has also.
You will find that some hardware needs "special drivers". What that means is the OS doesn't have them in it's "cache" of available ones and the "generic" ones it would use for that particular type of device are "insufficient" to properly run the piece of
hardware along with the others your PC uses. So, you add files.
If you have multiple users on your PC, you will be requiring that the OS employs
a different set of files than if you are a single user.
If your PC was sold to you by a manufacturer of PCs, then another set of files
placed on your HDD is involved to accommodate system recovery than the ones
placed by the windows operating system CD as sold by Microsoft.
It is complex.
People study this subject, and make recommendations based on user preferences
and requirements when advising which files are
just THE basic things that are needed for Windows to actually 'be alive'.
You are right to question it.
The startup database we have here at BC can be very helpful in identifying
files, not only those that are starting up malware programs, but many of those that
are typically running from the start in normal conditions a user will find on their PC, too.
As a step in the direction of being sure you don't delete any files you need, pay close attention to what you are doing with your PC. If you never use some programs, thats a fact. If you might use a program occasionally, thats another fact.
Being aware of the fact some people operate their PC with winXP that has a
"footprint" of considerably less that 2 GB on the HD should tell you that all of the OS
is not needed. It's up to you to decide what is needed and what is not, though.
Guidelines are available online at various places.
Programs are available to help make determinations.
Programs that are called "XPLite" or similar exist also, using "pre-determined"
selective deletion of files normally available in the windows OS.
A website detailing the appropriate use of Services in NT based windows versions is
also available. It all depends on what you want to learn, and what you want to do with your PC, St_Anger
well, if i need to delete everything, for whatever reason, i will know what not to delete, so i dont screw my windows up big time,
Deleting everything is exactly what is required in order to re-load the OS freshly. Nothing remains on your HD after the first step in the process.
Each of the file systems typically in use, FAT32 & NTFS, require formatting
of the HD. The formatting comes after the partitioning
, which is when the HD is made to be able to accept a Windows-type OS. HD manufacturers make the hard drives able to use other types of OS, too.
Each partition made has a purpose, always one that is primary & can be "booted from" is needed. Many times the entire drive is considered this, but optionally one can divide the physical drive into what the windows OS will recognize a separate disks, and advantages exist when doing this.
The combination of re-partitioning & re-formatting will always wipe your data off the drive ... including all previous OS folders/files and anything else.
It needs to be "stressed" that PC manufacturers that "pre-load" Windows for re-selling it to a buyer can not have this process done without the user having a
CD that will restore the OS files. Often special techniques are involved that essentially allow for deletion of partititions selectively, since one partition exists that has files the particular brand of computer uses, and they do not get "wiped" when you restore new files to your hard drive.
Once the necessary steps are taken, then the original OS files are copied from CD (or Floppy Disk in some cases of the older OS in particular) to the newly-ready "blank" HD and you end up with a Windows OS without all of the stuff you did to it
that slowed it down or whatever caused a problem.
It took about as long to type this information for you as it would to complete the
entire process of re-loading winXP, BTW.