19-03-2015, 02:26 PM
Often, when reporting a computer problem, people are advised to delete their cookies and delete the temporary files that are used by their web browsers, operating systems and other applications.
OK, this generally doesn't hurt - providing nothing gets deleted in error - but it does cause inconvenience. Cookies are used to provide a lot of "convenience" to users of web sites. Not to mention essential functionality in some cases. For example, you wouldn't be able to log in to this website without cookies.
Can these files slow down your machine?
Given a machine that was made this side of the Millennium, I've never understood why people think that cookies and temporary files would cause a computer to slow down.
Yes, if your hard drive is close to being full, then that might cause files to become fragmented, and that might cause the computer to start a bit more slowly, and perhaps other applications might take longer to start. So freeing up space might help in that particular circumstance. Though frankly, you are much better off buying a new hard drive, which will not only have more space, but will almost certainly be faster than the old one (certainly, that's my experience). They are not expensive, relative the cost of your data.
But...
Temporary files can build up, especially if you are a heavy user, so they might take up a significant amount of space. Windows provides a "Disk Cleanup" facility, which is much safer than manually deleting the files. To use this, follow these instructions:
What are these files, and what might they do?
A file only does anything when it's being executed. Or, when an application is reading the file (e.g. Acrobat Reader displaying a .PDF service manual).
So what's the difference between these "temp" files and all the photographs and service manual PDFs you've stored on the hard drive?
Basically, these files are totally benign. OK, that might be different if you did execute them, but you wouldn't do that, right?
More about cookies
Cookies aren't executable files, and as they are text files that are usually less than 1000 bytes, they aren't making much of a dent in your shiny 1TB HDD
Actually, Firefox stores all cookies in one large file. Only Firefox reads this file, and Filefox manages the structure of this file in its own way. There is no way that a cookie can cause the operating system any problems at all.
Let's clear this up once and for all:
What is a cookie?
A cookie is a "key-value pair". In other words a variable and a value. Mathematically, we might write "let X=360". That's a "key-value pair", where "X" is the key, and "360" is the value. So, if I'm writing a website that allows visitors to change the size of the text, I might store that setting in a cookie so that every subsequent page is viewed at the same font size.
Who can see my cookies?
Only the website that creates the cookie is able to read it. There is nothing that I can add to this website to read other cookies. There is no way that I, as a web developer, could find out anything about your banking details or Amazon orders.
I have many thousands of cookies on this machine. Don't worry about them!
What about temporary internet files?
When you view a web page, a file is downloaded to your machine and the web browser renders the contents into the document you are reading now. This file is HTML or XML, and is pretty easy to understand.
In addition, there might be some images - each of these is downloaded separately and held on your machine for the web browser to use. Likewise, there might be other files, including .CSS files (which determine the look of the page) and some .JS files (for any interactive elements). All of these files sit on a local "cache" on your hard drive.
Now, when you go to another page on the same website, the HTML page (the content) will be different, but things like the logo will be the same. Chances are, the .CSS and .JS will also be the same. We already have these, so why download them again? To save generating traffic needlessly, your browser will simply use the copies it already has in the cache.
These files sit on an area of your hard drive, and they are actually quite hard to find manually. That's intentional. They are totally benign. Even if somehow one of these files was a really nasty virus, it is still benign until it is executed. Remember, a virus is just a collection of 0s and 1s - it can only do any harm once it is being executed by the CPU, and to get to that stage, the operating system has to load the file into memory (RAM). If it's just sat on your hard drive, it's not in RAM, so it's not being executed.
Modern browsers manage their cache of temporary internet files. You tell your browser how much space they should occupy, and the browser will ensure that limit is not exceeded (by deleting the oldest files to free up space as needed). Out of the box, your browser will come with sensible settings, and there is no need to change them - but you can if you wish.
Summary:
In short, deleting your cookies and temporary internet files might give you a warm feeling - in the same way that cleaning your car might - but they won't make your computer (or your car) go any faster or be more secure - unless your HDD really is full up.
OK, this generally doesn't hurt - providing nothing gets deleted in error - but it does cause inconvenience. Cookies are used to provide a lot of "convenience" to users of web sites. Not to mention essential functionality in some cases. For example, you wouldn't be able to log in to this website without cookies.
Can these files slow down your machine?
Given a machine that was made this side of the Millennium, I've never understood why people think that cookies and temporary files would cause a computer to slow down.
Yes, if your hard drive is close to being full, then that might cause files to become fragmented, and that might cause the computer to start a bit more slowly, and perhaps other applications might take longer to start. So freeing up space might help in that particular circumstance. Though frankly, you are much better off buying a new hard drive, which will not only have more space, but will almost certainly be faster than the old one (certainly, that's my experience). They are not expensive, relative the cost of your data.
But...
Temporary files can build up, especially if you are a heavy user, so they might take up a significant amount of space. Windows provides a "Disk Cleanup" facility, which is much safer than manually deleting the files. To use this, follow these instructions:
- Open up Windows Explorer. The easiest way to do that is to click on Start, and move to "Computer" (Windows 7). Or, you can press "E" while holding down the Windows button on the keyboard.
- Right-click on the C: drive. It might be called "System", but you can call it anything you like.
- Click on "Properties.
- You should see a pie-chart showing you how full the disc is. There should be a button called "Disk Cleanup" to the right of that - click it...
- After a short delay, another box appears with a breakdown of the potential space savings. Click on "Clean up system files", and you'll get that space back.
What are these files, and what might they do?
A file only does anything when it's being executed. Or, when an application is reading the file (e.g. Acrobat Reader displaying a .PDF service manual).
So what's the difference between these "temp" files and all the photographs and service manual PDFs you've stored on the hard drive?
Basically, these files are totally benign. OK, that might be different if you did execute them, but you wouldn't do that, right?
More about cookies
Cookies aren't executable files, and as they are text files that are usually less than 1000 bytes, they aren't making much of a dent in your shiny 1TB HDD
Actually, Firefox stores all cookies in one large file. Only Firefox reads this file, and Filefox manages the structure of this file in its own way. There is no way that a cookie can cause the operating system any problems at all.
Let's clear this up once and for all:
What is a cookie?
A cookie is a "key-value pair". In other words a variable and a value. Mathematically, we might write "let X=360". That's a "key-value pair", where "X" is the key, and "360" is the value. So, if I'm writing a website that allows visitors to change the size of the text, I might store that setting in a cookie so that every subsequent page is viewed at the same font size.
Who can see my cookies?
Only the website that creates the cookie is able to read it. There is nothing that I can add to this website to read other cookies. There is no way that I, as a web developer, could find out anything about your banking details or Amazon orders.
I have many thousands of cookies on this machine. Don't worry about them!
What about temporary internet files?
When you view a web page, a file is downloaded to your machine and the web browser renders the contents into the document you are reading now. This file is HTML or XML, and is pretty easy to understand.
In addition, there might be some images - each of these is downloaded separately and held on your machine for the web browser to use. Likewise, there might be other files, including .CSS files (which determine the look of the page) and some .JS files (for any interactive elements). All of these files sit on a local "cache" on your hard drive.
Now, when you go to another page on the same website, the HTML page (the content) will be different, but things like the logo will be the same. Chances are, the .CSS and .JS will also be the same. We already have these, so why download them again? To save generating traffic needlessly, your browser will simply use the copies it already has in the cache.
These files sit on an area of your hard drive, and they are actually quite hard to find manually. That's intentional. They are totally benign. Even if somehow one of these files was a really nasty virus, it is still benign until it is executed. Remember, a virus is just a collection of 0s and 1s - it can only do any harm once it is being executed by the CPU, and to get to that stage, the operating system has to load the file into memory (RAM). If it's just sat on your hard drive, it's not in RAM, so it's not being executed.
Modern browsers manage their cache of temporary internet files. You tell your browser how much space they should occupy, and the browser will ensure that limit is not exceeded (by deleting the oldest files to free up space as needed). Out of the box, your browser will come with sensible settings, and there is no need to change them - but you can if you wish.
Summary:
In short, deleting your cookies and temporary internet files might give you a warm feeling - in the same way that cleaning your car might - but they won't make your computer (or your car) go any faster or be more secure - unless your HDD really is full up.
