usb startup drive w/ 128MB persistence file cannot be boot when it is locked (read only)

[charles]

lambda r091101 and before version, I am looking for a system that 100% virus free. Here I found it usb startup drive w/o persistence file. However, I cannot add google toolbar on it unless it has persistence file. I would like to save my setting and add function on it. Then lock it and pass to my kids. In that case I can save half day in restoring system. Whenever virus attack my kids' computers, my order is " just reset it "