Try using the compatibility mode.

What is the compatibility mode?

Compatibility mode allows you to run - even install programs/drivers, etc. from an emulation of XP or earlier OS.
Plus being a 2007 product there maybe a fix out or coming soon from software maker [not MS]
You may have to do a help/search/troubleshoot[or compatibility]/why won't my software work to open wizard.
Hopefully I will have time tomorrow to find an easier path to the wizard -been too busy to find and only got final Vista 4 days ago.
Have RC1 on this computer and what works on it won't work on final release on my laptop.

I tried compatability mode for Peachtree 2006, no sucess. Let me know if you have any luck?

I think the 2007 version of Peachtree uses pervasive SQL
did you check out if pervasive has any patches to make their SQL version compatible with Vista?

http://www.peachtree.com/support/vista/default.cfm?WT.mc_id=RD_peachtree.com/vista#2007
 
here are the known incompatibilites with vista

Regretfully this is to be expected when a new OS comes to the market which is a shame..

If you have an older OS such as Windows 2000 or XP, you could try running Virtual PC (free from MS), install Windows and then run Peachtree on that.