Converting Windows App written on XP to Windows 7

I inherited a huge code base which was written to work on Windows XP. Now开发者_如何学编程 we would like to migrate to Windows 7. I do not know what is the proper way to go about this. What is the proper approach to do the above task? I did some googling on differences between XP and Windows 7 but I do not get any proper links which describe how the internals of 7 differ from XP. Any links will be appreciated.

Usually how do S/W developers migrate their code/apps written for one version of OS say Vista to Windows 7?

I sell an autoupdate solution (AutoUpdate+, minor plug) and so have lots of experience porting Windows apps to the latest releases, and yet still maintaining backwards compatibility. Porting from Windows XP to Windows 7 can be a big challenge (there should be almost no difference in a move from Windows Vista to Window 7).

Window XP doesn't care where your application exists, and hence programmers would dump both their application and support logic (log files, config files, user profiles etc.) into the same location under "C:\Program Files\". Take this application to Windows 7 and you'll start finding some unusual behaviors. For starters, you will notice that files seem to 'disappear'. Instead of a log file being modified under the common Program Files location, you may end up with multiple, and separate, copies for each user under "Compatibility / Program Files". Windows Vista/7 introduced file system virtualization, and will now create separate user instances of files to ensure to ensure that each user has their own secure copy.

Another problem you will encounter on Windows Vista, and to a lesser extent on Windows 7, is User Account Control (UAC) prompts. It's similar to the issue above, in that new security restrictions will now cause Windows Vista/7 to prompt the user for approval to proceed. The most noticeable area where this occurs is when you are tampering with executable files in sensitive directories, installing applications and drivers, and sometimes when trying to self-update an app (the abovementioned app actually works around these prompts with some smart logic).

So in short, security changes are the biggest difference between Windows XP and Windows Vista/7. Your best start is to separate application logic (binaries) from supporting logic, by putting the latter into user specific directories. Some apps may never be fixable and can be forced instead to work in Compatibility Mode or to launch always under the Admin account context --- poor workarounds, but may be suitable in your company.

Simon @ http://AutoUpdatePlus.com

There are three parts to the migration. First, make it just plain work. This means fixing up hardcoded file paths (there's no more Documents and Settings), changing some of your save locations so you don't need to be elevated to work properly and don't rely on virtualization, changing some of your registry key locations for the same reason, and coping with high-DPI which might now be applied automatically based on screen size rather than as a user's choice.

Second, make it look and work like a Windows 7 application. Is your jumplist usable? Your thumbnail? You get some things for free, do you like what you get or would you like to take control? Are there obvious wins you could use like thumbnail buttons, jumplist tasks, taskbar overlays, etc. Don't surprise your users and don't disappoint your users. (Example of disappointment: VS 2008 and the crummy jumplists it offered. They had the excuse of being released before Windows 7 - you don't.)

Third, take advantage of Windows 7 to be greater than you otherwise would. Stop polling for network joins, file creation, hardware being plugged in, going on and off AC power etc and learn how to get notified when those things happen. Add touch support beyond what you get for free. Talk to a sensor or GPS for the first time, since Windows 7 makes it simpler than it ever was. That sort of thing.

1 is not optional. 2 is really not optional either, a year after Windows 7 is released. 3 will differentiate you and I recommend, once you get past 1 and 2, you look into it.

Basically Windows7 is a 4bit OS and so necessarily runs on a 64bit processor environment. XP has 32bit as well as 4 bit flavours. If your application is for the 32bit version of XP, in that case, the major migration means making the application run on 4bit OS effectively.

The basic steps can be something like this:

1. Make it compatible to 64bit win7. So you may just compile the code off a win7 machine (on 64bit). If the compilation works fine, you might be able to run the app successfully.

2. The first step just allows to move ahead. But your application might not be effective. In that case, you might have to review the code for any specific implementation coupled on 32bit os and upgrade them to take advantage of 64bit OS.

The major advantages on 64bit OS is higher address-ability (so access more RAM) and also cache etc.

I did some googling on differences between XP and Windows 7 but I do not get any proper links which describe how the internals of 7 differ from XP. Any links will be appreciated.

API diff report between XP and Vista: https://abi-laboratory.pro/compatibility/Windows_5.0_to_Windows_6.0/x86_64/abi_compat_report.html

API diff report between Vista and 7: https://abi-laboratory.pro/compatibility/Windows_6.0_to_Windows_7.0/x86_64/abi_compat_report.html

The reports are generated by the abi-compliance-checker tool.