Do I need to keep all the various versions of Microsoft .NET Framework on my computer? In the “Add or Remove Programs,” I have 1.1, 2.0, and 3.0 listed. Will all my programs work if I delete the older versions?
I noticed that I also have many different versions of Java or J2SE Runtime Enviroment–can I safely delete the older ones? If so, I wonder why the new versions don’t just overwrite the older files?
You need to keep the .NET stuff. Older programs won’t generally work with the new versions. I don’t know if that is a problem with the programs or with .NET, but it is true of both open source and paid software.
I think you can remove the older version of JAVA. At least I have and I haven’t noticed any problems.
Programs are specifically written for specific versions of .NET framework, so if you have applications using the 1.1, they will not work unless you have it installed.
You probably can try uninstalling 1.1, and if something stops working, simply reinstall the 1.1 framework.
As a variation of this question, I have a program that requires it, but suddenly won’t open and says I need the latest version. Went to MS Update, tried to download that upgrade version, but it failed, even after two attempts.
I only have one version (2.0, I think) in the Remove Programs list. Would it be safe to delete that and then try to download and install the upgrade version?
If not, what is wrong with it? Corrupted somehow?
Probably the program is looking for the “latest version” as of the date it was written, which may be the 1.1 version of the .NET Framework, which you can download from Microsoft.
.Net is designed a little differently from other environments when it comes to versioning. So rules of thumb learned from other software installs are not necesarily valid when it comes to .Net
Any given end-user application is designed for a particular version of .Net and will insist on that version and that version alone.
Unlike other environments (e.g. java), .Net was designed to have multiple versions of the Framework installed without interference between them. Version 2 does not depend in any sense on version 1.1. They’re separate or 'side-by-side" in the jargon.
The expectation is that you will have Framework versions v.0, v1.1, v2.0, v3.0 & soon v3.5 installed on your box. Windows will keep them all straight and everything will be fine.
At some point in the distant future v1.0 & v1.1 will become obsolescent enough that they’ll drop off and ancient legacy apps from the Dark Ages of, say, 2002 will not run.
From the point of view of a developer, the versions are upwards compatible. Code written for v1.0 will compile & run on v3.5. But from the point of view of the end user, each version is an independent island which knows how to run apps written for that island version.
This is true for the most part, but it should be pointed out that v3.0 and v3.5 are iterative upgrades from 2.0. That is, they basically extend the 2.0 architecture.