Environmental Variables control how the Operating System finds and uses files.
First do you know what the environmental variables
are? Where they are located? And why you would change them?
You do? Cool!
You don't? Well here is a short tutorial
In the "How To..." section there is a page called Performance Optimization.
This page details how to set different parameters to increase the response of
your Operating System such as how big your Paging File should be and why you
would take control of it instead of letting the Operating System decide how big
or small it would be. Also why you would want to store it preferably on a
different hard drive than the one the Operating System is on.
A variable in programming is a value that can be changed by substituting one value for another.
In the case of environmental variable the use of the % sign means this has a different value than the per cent sign, it could be a number, a string of numbers, a character, or a string of characters. The value in this case is in the registry, % will be a path to the value such as: C:\Windows\System32.
But consider this:
Once you change the variable then the old value is gone. It is written to the registry once you click the apply or Ok button.
So how do you recover the original values in the registry?
The only correct way is if you have made a backup of the registry keys that you were changing. Remember:
"Your recovery is only as good as your last backup."
If you don't have a back up to restore are you up the proverbial creek with out a paddle? Ummm, yes and no.
If you have access to another computer with the same OS you could export the key that you want to recover the
settings for and then import it. But that may make things worse, how do you know it is the same as the original values?
When you optimize your Operating System to get the best performance possible from the OS you change some
settings, for the most part you only change the path to your Temp files, this change allows you to select where the Temp files are written and insures rogue programs aren't putting temp files all over your storage.
If you open the Properties of My Computer and go to the Advanced tab you will see a button for "Environmental Variables" if you click it you will see two boxes, the top box is for your profile, this is mainly for the location of the Temp/TMP files.
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The box in the middle of the page is for the Operating System, there are only three
items there you should change:
- PATH: (Only add the drive and directory to your new temp folder!)
All other settings should not be changed!
I have written a couple of checklists, guides, and it is in three of my books: Performance Optimization
The Self Computer Repair Unleashed 2nd Edition E-Book.
Of all the things I have seen in my short Computer Tech career of 25+ years is how bad someone can muck up an OS by changing these