Several freshly minted Linux live (bootable) CDs boot with no problems in my desktop PC. However, when I attempt to boot any of these CDs on my Thinkpad iSeries 1400 laptop, I observe strings of read errors during the bootup process. Is this an indication that the CD/DVD-ROM in my laptop is failing? Thanks. Howard

Do other CDR disk read OK on the Thinkpad? If the disk in question is a CDRW then that could be an issue.

Make sure the CD is clean and free of major scratches. Try cleaning the laser lens if you can easily see it when the CD tray is ejected, or use a laser lens cleaning CD. .... A CD-R burned disk will work in virtually all optical drives, but a CD-RW or other type of burned disk may not read properly, and/or may not be found to be bootable, if the disk was not made in the drive it is read from. .... A common thing that can happen with ram, even ram that worked fine previously, is the ram has, or has developed, a poor connection in it's slot(s). This usually happens a long time after the ram was installed, but it can happen with new ram, or after moving the computer case from one place to another, and I've had even new modules that needed to have their contacts cleaned. See response 2 in this - try cleaning the contacts on the ram modules, and making sure the modules are properly seated: http://www.computing.net/hardware/w... For a laptop, you must remove both its main battery and AC adapter before you do that. ...... Did you change which ram you have installed? If you have, the ram has to be 100% compatible with the mboard main chipset's memory controller, or on some recent computers, compatible with the memory controller built into the cpu. Ram that works in another mboard , or any ram you buy or have lying around, may not work properly, or sometimes, not at all - even if it physically fits and is the right overall type (e.g. SDram, DDR, DDR2, etc.; PCxxxx, xxx mhz) for your mboard. In the worst cases of incompatibilty your mboard WILL NOT BOOT with it installed, and the mboard may not even beep - the ram has to be compatible with the mboard and it's chipset. See response 5 in this for some info about ram compatibilty, and some places where you can find out what will work in your mboard for sure: http://www.computing.net/hardware/w... Correction to that: Mushkin www.mushkin.com Once you know which module ID strings work in your mboard, you can get them from anywhere you like that has ram with those ID strings. If you have brand name ram, it is usually easy to look up whether it's ID string is in a list of compatible modules found by using your mboard or brand name system model number. If the ram is generic, that may be difficult or impossible. If in doubt, if you still have the ram that was installed previously, remove the new ram and try the old ram. If you do a ram test, do that AFTER having tried cleaning the contacts and making sure the ram is seated properly - otherwise any errors found may be FALSE. If the ram is incompatible with the chipset, it will likely FAIL a ram test - that is NOT a true indication of the ram being faulty - there is probably nothing wrong with it, and it will pass the test if installed in a mboard it is compatible with. If you want to try a memory diagnostic utility that takes a lot less time to run a full pass than memtest86 does, this one is pretty good - Microsoft's Windows Memory Diagnostic: http://oca.microsoft.com/en/windiag... It can be toggled to do a standard or a more comprehensive set of tests - use the default 6 test one first - if it passes one pass of that, use the latter one. A few of the tests in the latter set are intentionally slower. .... I encountered a strange problem yesterday. Problems reading the CD can apparently be caused by incompatible ram, even if it does pass memory tests. I had two modules installed - 256mb and 128mb PC133. They pass all Microsoft Windows Diagnostic ram tests individually and when both are installed, yet when both modules are installed, I got many errors reading the files from an XP Home original CD, after the initial files had been loaded successfuly, the C partition had been deleted, re-made, and formatted. Up until then, I had always assumed if the ram passed memory tests it should work fine with Setup. When I took out the 128mb module and then ran Setup, there was no problem reading the files on the CD.