I need to know when Avast will stop supporting/providing new virus definitions for Windows Vista and Windows 7. Avira provides this information and it’s useful to help decide which OS to upgrade to and when to upgrade without being forced to upgrade because the vendor has stopped support/definitions. I do not want to go with W8 at this time because of the tablet GUI.
As XP is still supported then I do not see when the support for Vista, 7 will end . Win2K is only being phased out this year (although some systems may still be able to get it to work )
It is not that Avast! will stop VPS for an OS, but when an Avast! version will stop getting those VPS. VPS for Avast! version 4 will end this year. However, as essexboy said above, there are users still running Windows 2000 with Avast! v. 5, 6, and even 7. So even when the next Avast! 8 comes out, it will support Windows XP, Vista, W7 and W8. So I imagine that you will have support for Vista and W7 for several more years.
I’ve got XP and Vista machines that I see no need to upgrade ever except for the forced obsolescence of not being able to get current antivirus definitions. I’m trying to decide between upgrading to W7 before it gets priced out of reach because of the W8 release, or take advantage of the $40 W8 upgrade offer which ends Jan 31, 2013 even though I hate the W8 GUI. So it would be nice to findout when Vista/W7 antivirus definitions will end since I don’t imagine Microsoft will bring the Start Menu back to Windows 9.
Not being able to get the latest VPS for XP or Vista could be caused by issues in your program or issues in Avast! servers which we have had a couple of them lately. However they were quickly repaired and new VPS emited.
That I can not help. It is your choice, but be assured that W7 will be around for a while yet.
Since Microsoft itself will be offering extended support for XP through 4/8/2014, for Vista through 4/11/2017, and for Win7 through 1/14/2020, I believe it’s safe to assume that Avast will do so for at least as long [that is to say, in avast’s latest version(s). As Iroc9555 noted, this does not mean that avast will continue such support for its older versions, e.g. avast4]. Avast offered continued support for WinME long after just about every other anti-virus program had abandoned it.
You can run W8 using one of the many free “Start” apps created by third parties and you will never see the Modern UI unless you want to. W7 is a good product but it has had enough updates so that it can be kind of funky at times. To solve that though all you have to do is a clean install of W7 from the original CD or file and reformat the “C” drive in the process and apply all the W7 updates. Doing this gives you a clean Registry and clean “Users” directory tree. Then reinstall all your software. I have done this recently on two of my computers and W7 has been humming along as good as it ever has. 
W8 however, does have better security, handles memory better and overall is a bit faster. I took advantage of the $34 offer but will not replace W7 with W8 probaly until W8-SP1 though it could be a bit earlier depending on how it is working with my other software. For example right now there are still some problems with running avast! 7 on W8 so it is better to wait.
How do you know this to be true (Win2K being phased out this year)? Do you mean avast! 8 won’t support it? Why couldn’t a user just stick with version 7 if he had Windows 2000? There are still 4.8 users, and will be for quite some time!