Online but told offline?

I’ve been running WinXP for 5 years with no problems. In the last month while online when I attempt to do ‘whatever’ I get a dialog box telling me I can’t do that offline. I’ve tried all kinds of workarounds but the problem persists, It’s driving me insane.
Sometimes the workarounds work, sometimes not.
I often have to close everything and connect again when the problem starts again. Does anyone have any ideas?
Thank you for your time and attention to this matter. Jack Manger jbm125@icontech.com