Hey Techspotters, I'm hoping this is the right place to post this, if it isn't let me know. I had a recurring BSOD problem for a month or two, which was eventually traced to Panda IS (thanks peterdiva) and has been sorted by switching to Kaspersky IS 7.0. To rule out faulty RAM, and because I fancied upgrading anyway, I added 2GB of DDR2 memory, two 1GB sticks to go with my existing 2x512MB, the following day (yesterday). These were standard Crucial sticks, 'guaranteed compatible' and installed as per the instructions, in the two empty slots. Strangely though, ever since, Windows has been starting up extremely weirdly. Boot to log-on is fine, no problems there, but logging on is where it goes off the rails. It loads the taskbar, with one icon in the tray (safely remove hardware, for my USB wireless adapter) and then sits and does nothing for a while. The mouse moves, the desktop shows, but clicking does nowt and Alt+Ctrl+Del doesn't respond. Eventually (ten minutes or so) the case hums, the fan starts up, and everything starts as usual, icons in the tray, start menu, everything works. And there's no more problems until I next start it up. It's bizarre, I can't find a reason for it all, and as you can imagine, ten-minute start-up is not ideal. Task Manager shows all 3GB of RAM are physically there, the BIOS recognises the new memory, so I haven't the foggiest idea what's going on. And the Virtual PF is set to system managed, in case that has any bearing. I'd appreciate any ideas you could throw at me, at the moment I'm away back into the case to check I didn't knock a wire loose when I was guddling around in there. I don't think Kaspersky's causing the bother, hope not anyway. Cheers, sorry for rambling a bit :blush: BP.