What is .NET?

[silverback]

Can I get a simple explanation of what MS.NET is and what it's for? It seems to be taking over my PC.
I already had Microsoft .NET Framework 2.0, Microsoft .NET Framework 3.0, Microsoft .NET Framework 3.5 on the PC - I know not what for - and yesterday I bought a new SatNav for the car. When I plugged it in to get the latest map updates, the first thing it said was that I didn't have the right .NET product and proceeded to download Microsoft .NET Framework 4 Client Profile.
These .NET products are 183Mb, 208Mb, 28.4Mb and 117Mb respectively - half a gigabyte of program!
Then, when I logged on today, I had to download 38Mb of Microsoft high priority updates for Framework 4. 38Mb!!! Doesn't anyone worry about patch sizes anymore?
What's going on, please?
Thanks
Silverback

[StuartR]

.NET is a programming environment. The downloadable stuff that you have on your PC enables you to run programs that people have developed using .NET. Think of it as a set of run time libraries that can be shared by lots of different programs.

Programs that were written using an old version of .NET will require that old version to be available on your computer, which is why you have so many different versions.

[HansV]

The .NET Framework consists of the supporting files that you need to be able to run programs written in one of the programming languages in the Visual Studio family from Microsoft, such as VB.Net or Visual C++. Each version of Visual Studio comes with a different set of supporting files, hence the multiple versions.

Unfortunately, the .NET Framework is ridiculously bloated, but there is nothing you can do against that - if you remove one of the versions, chances are that some programs won't work any more (and Windows Vista and 7 need the Framework themselves, I think).

On the other hand, what is half a gigabyte compared to today's hard disk sizes?

[silverback]

On the other hand, what is half a gigabyte compared to today's hard disk sizes?

Well, .21758% actually.

It's just me not moving with the times. I used to look after the COBOL runtime library for our (mainframe producing) computer company, and each change was subjected to inspection to ensure it wasn't getting 'bloated', as were all patches.

Each version of Visual Studio comes with a different set of supporting files, hence the multiple versions.

Seems like development is out of control!

Thanks to you and Stuart for letting me know what the stuff is.
I'll go and lie down again, now.

Silverback