W500 broke down for no apparent reason

Question

Dear all,
I have a W500 that worked fine for 4 years and suddenly started being faulty for no apparent reason.
I've searched the web and tried many fixes, but I still haven't been able to pinpoint the problem. At this point I suspect that the problem might implicate faulty hardware, though I am not sure. I would really appreciate any suggestions that could help me figure it out and (hopefully) fix it.
The laptop is a ~5 year-old W500 that came with Vista install but was upgraded to windows 7 after a couple of months. I made the BIOS upgrade at that point, but not since.
After trying to rescue it without success, I eventually reset the BIOS to default settings and reinstalled windows 7, and I am now able to use the computer but with many persisting problems.
Current symptoms
    Slow boot time (4-5 min until I can start using windows) with occasional failure to start windows (hangs for hours before log on screen, but without crashing)
    Initially failed to shut down, but uninstalling the dvd drive in windows seems to have fixed this.
    Black screen appears on two occasions during boot. (1) between the "please wait" screen and the log on screen, and (2) after logging after the "welcome" screen. Each stays for around a minute (I guess they also show on healthy systems but too short to be noticed)
    Windows is generally slow and prone to failures. Browsing windows explorer sometimes works fine, sometimes hangs for several tens of seconds. Launching programs takes an unreasonable amount of time (up to several minutes in some cases). Installing programs is incredibly slow and often fails.
    Initially, after reinstalling windows, it looked like windows explorer did not refresh itself automatically anymore: if I created a new folder for example, it would not appear until I hit the refresh button. Somehow, this issue seems to have resolved itself, perhaps when uninstalling the cdrom, but I couldn't swear.
    Booting in safe mode hangs after loading CLASSPNP.sys, which apparently is a recurring problem. In my case, after re-installing the OS it only hangs for 2-3 minutes and eventually safe mode successfully starts.
    Yesterday the graphics driver failed multiple times, which never occurred before (well, maybe once, and a long long time ago). The first time the computer restarted automatically, and the next couple of times the screen just went black but the computer was still running.
    Apparently I am unable to restore to factory state using the rescue&recovery environment. The partition which I believe to be the recovery partition (it has drive letter D: and no name, it guess this happened when installing the new OS) cannot be accessed from DOS (I/O error comes up, I am not sure if this is normal or not), and browsing it in windows explorer causes it to freeze. In safe mode it does appear in disk management, where is says 9.8GB, RAW, primary, healthy, 100% free space. Rescue and recovery environment does not start (perhaps as a consequence of this).
    Since reinstalling windows the fingerprint reader does not work, and the "mouse wheel" function of the touchpad is broken (looks like the drivers are missing, but I can live with that for now)
Additional details
As I mentioned above I've had this laptop for 4-5 years and it always worked properly without major glitches. Then one day windows suddenly failed to start without reason, although on rare occasions I was able to log in after a very long boot (which suggests to me that it might not be completely broken but just took forever to start up windows), but then it would also fail to shut down (hanged forever at the "windows is shutting down" screen.
Thinking back, the laptop did on rare occasions fail to start windows, but would always start the next time and never failed to shut down as far as I remember. Lately I also noticed freezing on some occasions, which at that time I thought might be related to the DVD because they seemed to happened only when the DVD was in use.
After many unsucessful attempts to recover the current system I reinstalled windows 7, and now windows is more or less running, but with the symptoms described above.
I've run chkdsk /F /R /B, sfc /scannow, and windows memory diagnostic multiple times, as well as several lenovo diagnostic tools (CPU, memory, optical, graphics and perhaps a couple of others); none of them returned any error (1 bad sector added to list by chkdsk last time it ran).
Questions
    Any suggestions/feedback?
    At this point, is there a chance it could help to reformat the entire drive and reinstall windows?
    In particular, I'm not sure why I need the recovery partition if I (1) it doesn't work and (2) I have an installation CD for the OS anyway.
Also, would it safe to remove the SERVICEV003 partition?
    I've read somewhere that to restore to factory state you need to mark the recovery partition as "active" - is this true, and could it be the reason that rescue&recovery environment does not start?
    Is it any use updating the BIOS at this point?
    Also, is there any chance that playing around with the BIOS config could result in a working configuration?
    If the problem is a hardware problem, how can I figure out which is the faulty component?
    Is it possible to completely disable, e.g., the DVD drive, without physically unplugging it (BIOS doesn't seem to allow this, and even though uninstalling it in windows seemed to fix the shutdown problem, I know that the DVD is still working because e.g. I can boot from it).
    Is there a way to completely disable one of the graphics card to check whether problem could come from it?
    I've been considering pulling out the HD and memory to check if there is any misconnection/dirty connector. Is is even worth trying (I usually try refrain as much as possible from messing with laptop's inside) ?
I will update if I remember anything important or if there is any major new development.
Thanks in advance for your help!

Answer 1

137 attempted reallocations with 6 currently pending. Your drive is probably on its way out.
Back-up your data immediately. You could try running SpinRite or HDD Regenerator on the drive to try and fix it, but chances are you should just replace it.
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