VS 2010 Visual Basic 2910 Publish for Win XP

Hello, a few posts back we had some discusion about publish project created in Visual Basic 2010 would also work for window XP, but with instaling .Net Framework 4. True, but there is one problem. I have publish my project, set it with wizard, so if you dont have proper .Net Framework, it would install it. Then I try my project on mini laptop, which have installed Win XP SP3 (1,66 MHz, 1 GB RAM, 8 GB HDD - old but works). Setup for application work, and also it notice me, that I have to install .Net Framwork 4, but for that I need to have 4 GB of free space, and my application have only 10 MB require. 4 GB for 10 MB application, it seems too much.

What should I do? Is converting project from VB 2010 to VB 2008 good idea, any other sugestions?

Thanks for answers...