What is Microsoft .NET Framework and Do I Need It?

August 5, 2009

in advanced computing,Windows

by David Hakala

When you go to update Windows on the Microsoft update Web site, you have the option to select which specific updates you want to download and install. One update you may see is “Microsoft .NET Framework.” As of this writing, it is a whopping 284 MB package. Should you download and install it?

The .NET Framework is a huge collection of programs that creates a virtual machine in your computer’s RAM. (See What Is Virtualization, A Virtual Machine, and a Virtual PC?) Programs written by third parties for the .NET Framework do not have to worry about the different configurations of the machines on which they run, they use the known capabilities of the virtual machine. This makes programming easier and allows creation of programs that do interesting but non-essential things.

Most people don’t need the .NET Framework. It should be installed only if there is at least one specific program you can’t live without that requires it. Removing the .NET Framework will not harm your computer.

If you go to the Add/Remove Programs console of Windows, you may see several versions of the .NET Framework installed. Each expands and relies upon the capabilities of earlier versions. If you decide to remove the .NET Framework, you need to remove each version in reverse order, i. e., version 3.5 first, then 2.0, then 1.1. You will need to reboot to make the removal effective.

I like my computer to boot fully without my participation, going from power-on to Windows desktop without pausing for me to enter a username and password or click on my user icon at the Welcome screen. It won’t do that when the .NET Framework is installed because the framework requires its own user account named “ASP .NET Machine.” The computer doesn’t know which user is logging on so it waits for me to tell it. I’d rather be making coffee, so I removed the .NET Framework and deleted its user account. (Go to User Accounts in Control Panel.) When the coffee’s ready, so is my computer.

David Hakala has perpetrated technology tutorials since 1988 in addition to committing tech journalism, documentation, Web sites, marketing collateral, and profitable prose in general. His complete rap sheet can be seen at


Sonny 08.13.09 at 6:07 am

My computer boots from Power Off onto the Windows (XP Pro) desktop without any pause or login procedures, and has .Net Frameworks 1 thru 3.5. So coffee and computers with .Net can be ready at the same time!

Alberto 11.02.09 at 8:00 pm

Sonny is right, even if it prompted you to login to the account created by .net framework (which I believe the newer versions don’t) all you’d have to do is google download powertoys then look for tweakui, then open it under programs, powertoys, tweakui, under autologin fill in your user and pass and it’ll login automatically. .net framework is required by more applications everyday (including quickbooks) and shouldn’t be removed unless you are sure you don’t need it.

Keith 03.19.10 at 4:58 am

Thanks Alberto, I have a few apps that require the .net framework but it’s mostly invisable so I could not think of one; quickbooks is one I use. My system is pasword protected (10 characters, non dictionary with shift…) so I never noticed the coffee issue. Happy Friday all 🙂

Sanja 06.17.10 at 12:21 am

I tried to install a program (Virtual Hair Makeover) and it said it requires Microsoft .NET Framework. So, I downloaded the framework and it STILL didn’t work. Needless to say, I gave up installing that program. Then I did a little research and discovered that I already had a Microsoft .NET Framework installed on my computer, just a lower version (2.0) and the new one I downloaded was 4.0. Now, the question is: Will I have problems with my previous applications that used to run well on 2.0? Do I have both versions of framework now (because I didn’t uninstall the old one)? Can they both co-exist and work together?

thecarpy 07.16.10 at 9:06 am

No, you will not have issues, .Net has been designed to allow you to install 3.5, 3.0, 1.0, 1.1 and 2.0 in any order, does not really matter. However, the annoying thing with .Net is, that programs written for 1.0 will not run in 3.0, they specifically require 1.0, which is a pain. So you quickly end up with gazzillions of different versions, so much so that I refuse to install programs requiring .Net on my freshly installed system.

Developers should stick to Java or native code, not .Net crap.

Nana 09.25.10 at 4:19 pm

I installed Microsoft .NET Framework 2.0 on my windows 7 virtual pc with an xp os. After installing it it does not display in the IIS console but it appears under the list of installed programs. Please help.

Nana 09.25.10 at 4:24 pm

I installed Microsoft .NET Framework 2.0 on a virtual PC installed on a windows 7 os. the vitual pc has got an xp os. after installing it, it does not show in the IIS but show under the list of installed programs. Please how do i get it to appear in the ISS for me to enable ASP.

Denny 12.23.10 at 4:53 pm

I’m running an HP laptop from 2003 with XP. The RAM is small but I’ve always kept my internet security current and updated through Windows. Overall the laptop still performs quite well considering it’s age. For some time I noticed that it seemed to have a little lag time processing things like opening programs etc. I got to looking at the installed programs and was looking at all the space being taken up by .NET Framework and I was appalled. I did some research online and from what I read it’s used by website developers and the like for programming. I don’t do any of that so I uninstalled all .NET versions. Thankfully everything is running smoothly. I have done further reading online and come to find out many programs rely on .NET to function and run properly. If I had known that before I uninstalled maybe I would have thought twice.

I’m a very simple internet user and don’t do as much with my laptop as I used too. Pay some bills online, send an email once in awhile, surf the internet and do a little shopping and that’s about it. Since uninstalling .NET I have had no problems. If you want to uninstall too make sure you uninstall the latest version and end with the oldest.

My uninstall took a couple hours cause the files are so large, but I did it on my nightshift while I was sitting around anyway. To simplify a little further the latest version has the highest number and will should have the most recent install date. At the time of typing this 4.0 is the lastest, so start with that or the next number down that is on your system. If there are updates shown like was on my laptop make sure you also uninstall those in order to the regular version. Think of the uninstall like this: If you’re gonna tear down a house you start from the top and work your way down. You can’t take out the foundation before you tear down the roof, walls and floor. Version 4.0 for .NET woul be like the roof on a house it has to be removed before the walls and windows and onward in succession til the foundation is gone.

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