I've had my IBM ThinkPad 600E in storage for about 4 years. I turn it on and get error messages 161 and 163. I was also getting the date and time message coming up, too. Also what was happening is that after I set the date and time, this blinking screen that says OFF and ON would keep flashing. OFF would have a circle shape and a long, upright dash for OFF. No matter what I do, I cant get past that. A friend was once able to bypass this and actually get to the desktop, but I never was able to. Error 161 and 163 as I read on other forums points to the CMOS battery needing to be replaced. So I ordered the part from IBM and replaced it and I am still getting the clock/date set feature coming up and then that flashing ON and OFF thing again that I cannot get past. Any ideas what is going on here? Thank you!

MAN! I'm not familiar with that error Do you have or know how to download the "hardware maintenance manual?" Sounds like you know how to get into bios/setup? There is a diagnostics utility built into the bios. What do you have, floppy, CDROM, or both? YOu might pull out ALL removeable hardware, meaning extra added memory, the hard drive, and no PCMCIA cards. Now try and boot either from a CD or floppy and see what happens.

http://www.atbatt.com/product/ItemID/5359.asp

Errors 161 and 163 mean that the CMOS battery is dead, and that the time and date settings have been lost. To clear it, install a good CMOS battery and boot. Set the time and date - do NOT just accept the date offered, this will not work, it has to be changed. Reboot. If this has not worked I would suspect that the battery you put in is faulty. You do not need to get these from IBM, they are a standard item, which should be available in any larger high street. My Thinkpad uses a CR2025, yours may be different, but I suspect IBM charge a fortune. If you can, put a meter on the battery to check it is working - oh, and make sure you have put it in the right way up.

oldfogey,CR2025 is the correct battery.{serafinsgirl}I would follow oldfogey's advice,Maybe you can take the laptop with you to buy the battery,just as a precaution.

I'm having exactly the same problem with a friend's Thinkpad 770. I've replaced the battery, which registers just over 3V as a fresh one should, and it's definitely the right way up. It won't hold the system time/date: I change it, next reboot you get "0>1" and next reboot the system time/date's back where it was in 2000. You can't get into the bios (Easy-Setup) and the hardware reference manual at ftp://ftp.software.ibm.com/pc/pccbbs/mobiles/770tref.pdf doesn't help either. Any ideas?

... further to my previous post I've solved the problem. Though more by luck than by judgment. I tried plugging in the external floppy drive. With that plugged in, after a couple of attempts I did get into the BIOS (holding F1 on startup). I then reset the settings, set the time/date and ran a full system test. Everything came out as "OK". Next time I rebooted the machine, it booted properly into Windows. I hope this works for you too, serafinsgirl; most of the other posts I've read seem to say that if replacing the battery doesn't work then the mainboard would need replacing.