I changed from my exsisting Norton Internet Security and installed the new Norton Internet Security with Backup. Works perfect on my 3 Win7 Professional pcs & on my Win XP pc. Problem is the fact that it installs fine on my 3 Win XPmodes, but when exit, it no longer loads (error 8504,104). Have used the Norton Internet Security for years on XPmode. Yes I performed the usual Norton removal & reinstall method twice, but same results. I can go back to previous Norton & use it until it expires then decide which to do, pay for renewal or just get a free ASPR security. Good but not nearly as secure and Norton's. This problem will put a Norton bad taste in businesses mouths who have to use XPmode for excellent software that cannot be upgraded & no XP pcs to use it on.