Hey David,
1) What is the difference between wyBuild and wyUpdate?
With wyBuild you design and build the updates. wyUpdate, on the other hand does the actual updating. wyUpdate is the part you include with your application. The wyBuild installer (download it here) contains everything you need to start delivering updates of your apps to your users.
2) Will this software allow a windows service the ability to update itself, without user involvement?
This is a heavily requested feature that's coming in the next version (2.6.11). We're trying to get it out before the end of the week. You can start/stop services, install new services, and update services now, however it won't be completely silent. In wyBuild 2.6.11 you'll have the ability to update completely silently.
3) The updater is a cool tool but how did the user get the software on the computer in the first place, i.e. what installers are people using together with your product?
As we cover in the step-by-step walkthrough article, we recommend 1 of 3 installers: NSIS, Inno Setup, or WiX. We use NSIS for wyBuild's installer and you can use WiX to make MSI installers.
Making installers from wyBuild will be possible in the short term. I can't put a date on it yet, but it's before the year is out. We will probably include WiX with wyBuild and just make it a "one-click" operation to make the MSI installer.
3b) Some installers include updaters, so besides the deep c# integration your software offers, which is very cool, are there any other advantages for your updater?
Yes, wyBuild, wyUpdate, and the AutomaticUpdater have many advantages over the limited updaters included with "professional" installation creators. The limited pseudo-updaters included with some install creators are simple bootstrappers; that is, they check for an update then they download the full exe or msi installer and just run it.
wyBuild, on the other hand, compares versions of your app and generates the smallest possible patch from the old version to the new version. This can save you big on bandwidth bills. Plus your customers will be able to get the updates faster. There are a thousand other advantages.
3c) Does this software have an install partner?
No, we don't recommend any "professional" installers. Mostly because all of the good installers are open source: NSIS, Inno Setup, or WiX. Microsoft uses WiX to build installers for a large portion of their software and NSIS is used by Mozilla (among others). In short, these aren't lightweight installers. They're trusted by small and large companies alike.
Eventually we'll integrate WiX in wyBuild to simplify the whole process.
4) If the application is installed with an msi, will uninstall work properly, presumably in the msi uninstaller I can run a command to remove the app folder, which would do the job.
Yes, there's a wyUpdate command ("wyUpdate.exe /uninstall") that will uninstall any newly added files, folders, registry, etc. You can call that as part of your MSI uninstaller and everything will uninstall cleanly. We can point you in the right direction if you need help.
5) I understand there is a new version which is due to arrive imminently, what new features will it have?
AutomaticUpdater that works in non-UI apps (Windows Services, console apps, etc.), silent wyUpdate options for updating non-.NET Windows Services, various wyBuild improvements, etc.
It's a "minor" upgrade (i.e. it's free for all our users).
6) (Side question) I need to ask the user during the installation if the user would like to install a SQL database, if the user chooses yes then I download and install SQL Express 2005, is there an easy installer which would allow me to ask this question?
There are lots of ways to do this. If you're using WiX, here's an article that shows how to detect whether it's installed or not: "How to detect SQL Server Express in WiX installer".
Many thanks for answering these questions.
No problem. If you have any other questions don't be afraid to ask.