i swapped HD today with clean install of windows 7, tried different memory module also........ worked for awhile and then hung up again
Bring up ADMIN Cmd prompt, type chkdsk /r /f , and press enter on your keyboard, then a Y, then reboot, it now checks your disk for errors and fixes them. I hate you are having to do all these things, you have to find a full diagnostics test somewhere. Also could be bad or going bad power cable going to your Hard Drive, works sometimes, sometimes not. If you take diagnostic tests and it's the motherboard if it is still under warranty, send it back for replacement, good luck. Have you gone into BIOS to make sure boot order is correct.
It also could be the Memory Module('s)! I would do the following: if 2 Memory Modules exist, take out one and test-run with just 1 module if that still produced same problem, remove exchange the Module and test-run again remove both Modules, and use a soft Pencil Rubber for to clean the connector feet of each module place 1 in and test-run again do the same for the next module have both back in and run You could try some Memory Test Apps, just, if you do, keep in mind, that those apps never be correct, they could still show all Ok, and it's just bogus! Also, a re-burn and/or update of the BIOS Software, may helps. As you already swapped the HDD and those problem persist, I do believe that those problem will mainly be Mainboard (and/or some of it's components) related. If there still Warranty on that machine, I would contact nearest Service Station.
I hate to sound like a pessimistic S.O.B. (even though I am a pessimistic S.O.B.) but I think the OP is stuck with what they have. Why would I suggest such a thing? Because I did a Google search on this issue and there are a lot of Lenovo G500 owners posting in a lot of forums - all having the same problem. Can't be a co-incidence. (And don't get me wrong, some of my favorite laptops over the years have been Thinkpad/Lenovo - a great majority of their products are top tier). But in my opinion, the G500 was released without being fully tested. Or they did test it, saw the problem and convinced themselves it could fixed after the fact. They can't all be winners. And I am amazed at the countless models of laptops that Lenovo, Dell, HP, etc. release every year.
likely its the power management in DSDT for Win 8. try this.. install linux with grub2 and use that bootmenu.. might have to play with acpi loading codes (cheatcodes)
I removed the DVD drive and it does not hang.... reconnect DVD and it hangs.... problem solved...... i am switching to an external DVD anyways .........Old school technique> (thx latin MCG)< that i had forgotten......duh
Then look for the firmware update online instead of decommissioning it altogether. Perhaps LatinMcG can help with the right one for your system model.