|See response 2 in this - try cleaning the contacts on the ram modules, and making sure the modules are properly seated:|
Some ram manufacturer's modules do not strictly adhere to the JEDEC standards that most mboards bioses use to determine ram settings.
In that case, the ram settings in the bios Setup that the bios has automatically chosen may not be correct.
Check the ram settings in your bios - the ram voltage, and the ram timing numbers - those should be the same as for the specs for the modules themselves. Often the ram voltage and timing numbers are printed on the label on the modules.
If the voltage setting or timings settings in the bios are different from the specs for the ram, change them in the bios. The timing numbers must be as close as you can get to the same, or slower timings (higher numbers = slower) - you won't notice the difference the slower settings make.
If you have a mix of different modules
- don't mix ram that different voltages are specified for - the bios will force the ram to use the lowest voltage, if "by spd" or similar is used (default settings) - ram that a higher voltage is specified for is more likely to not work properly in that situation.
- the bios settings must be those for the slowest timing settings of all the modules, or slower (higher numbers = slower).
You MAY be able to custom set the ram voltage to the higher ram voltage in the bios if you do NOT have the bios set to detect the ram "by SPD" or similar, however, you must NOT exceed the max voltage range for the modules that require a lower voltage, and that can be hard to determine, unless you can find detailed specs - e.g. if the ram is Kingston ram that doesn't have a brand name system specific part number, that info is easily found.
After you have checked those settings...
Test your ram.
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:
Windows Memory Diagnostic is limited to testing only the first 4 gigabytes (GB) of RAM.
It can be toggled (press T) 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.
If you don't have a floppy drive, see the Quick Start Information at that Microsoft link for how to make a bootable CD of the Windows Memory Diagnostic (you need Windiag.iso - you don't necessarily need to use the program they mention to add it to the CD).
NOTE that we have seen that the ram can pass diagnostics tests even when the settings for the ram in the bios are WRONG, but if the settings for the ram in the bios are NOT compatible with the rams specs, or set slower, you WILL have problems in the operating system itself.
Check your hard drive with the manufacturer's diagnostics.
See the latter part of response 1 in this:
If you don't have a floppy drive, you can get a CD image diagnostic utility from most hard drive manufacturer's web sites, but obviously you would need to make a burned CD, preferably a CD-R for best compatibility, on another computer if you need to.
Seagate's Seatools will test any brand of hard drive.
Do the long test.
The bootable Dos versions of SeaTools can be used even if Windows is not working properly.
If the hard drive itself tests okay, any data problems found can be fixed, one way or another.
Regarding your disk made from the ISO -
Try using a laser lens cleaning CD in the drive. If you don't have one you SHOULD have one. Most places that sell CDs or DVDs sell them, and even some "dollar" stores have them for a buck or two.
Or, if this is a laptop computer, eject the drive's tray and with no disk on the tray, wipe off the obvious laser lens with a tissue or a soft cloth.
All optical drives are more or less specific about which MEDIA - brands / types of burnable disks - can be used with them without a problem. A CD-R or DVD-R should work fine with nearly any optical drive that can read them, but other types of burnable disks may NOT read properly in a drive they were not made in.
E.g. The ONLY brand of burnable disks of ALL types LG drives are specified by the manufacturer of the drives to have no problem with are Verbatim disks (in North America - the brand is called something else in many other places in the world).