Just make sure you are using the most up to date version of the Desktop Manager. It's version 4.2 SP2. Also, I believe that you have to "install as admin." I don't use a Vista machine but I think you right click on the file to install and there is an option to install as admin or the like.
As far as the spending app, I'd probably just use the memo pad. I'm not familiar with anything like that. I'm not saying it doesn't exist, just that I'm not familiar with it. However, check out Handango or the other software vendors for that kind of stuff.
Hope this helps.