Three days ago, on Tuesday, I started up my Dell XPS15 laptop as usual, however something odd happened.

After the Windows logo, there was a black screen that lasted a really long time. Suspecting a virus, I shut it off and hopped into Safe Mode for scanning.

Well, after it was done loading all the files for safe mode, it took 15-20 minutes (I was too angry at it to really pay attention to the time to get it down to the minute) to go into Safe Mode. After it did, it was slow, but I attributed that to Safe Mode.

Did scans, found nothing. Checked System Restore. No restore points. Isn't it supposed to make points periodically?

I just let my laptop *attempt* to start up again after the Windows screen. After about ~10 minutes, it started up.

Ran scans, updated virus definitions, etc, found a TON of Trojans/PUPs/Adware which are all gone now. I can run any scan now and it won't find anything.

...the problem? The restart times are STILL incredibly long, my computer in regular function is slow as heck, various drivers keep mucking up (sound for instance I have to keep repairing). Something even got so badly damaged that I can't use the Windows 7 default (Aero) theme anymore. I tried repairing it using their option to do so... but it tells me I can't.


So today I found out the laptop has a diagnostics test it can do. Runs various tests to make sure everything is in working order.

Everything but one thing passes the test: My hard drive.
The message it gave was:

"Hard Drive DST Short Test

Error Code 0142
Msg: Error Code 2000-0142
Msg: Hard Drive 0 - self test unsuccessful. Status: 79
The given error code and message can be used by Technical
Support to help diagnose the problem.
Do you want to continue testing?"

Searching the error around... it's an error indicating hard drive failure.

I have everything backed up if I need to restore it to factory settings, as I have a backup from roughly two days after getting my laptop.

What should I do?

Also, I've ran various tools like Startup Repair and chkdsk several times. I can't even do a defrag because apparently some files needed to do it got badly damaged.
If it gets to the point where the self-diagnostics are reporting failure, the hard drive is probably failing. You should probably get everything you care about off of it and replace it. Laptop HDDs are pretty cheap, and you can probably open up the lappy sufficiently to replace it.
In response to Jp
Good news. It got fixed from a very thorough chkdsk, one I didn't do the other day.

I'm not sure if this does mean my hard drive is failing or not, but it's repaired now.

What I did to fix it (Windows 7):
1: Go into the Start menu and type in "cmd.exe"
2: Right-click and hit "Run as administrator"
3: When it opens, type in "chkdsk /b"
4: Restart the computer. This chkdsk WILL take awhile. I had 330GB or so to scan, took over 2 hours I think?
5: It should be resolved. Try defraging and such if allowed afterward. All of my issues were immediately fixed.

(also, getting a power strip to slightly buffer my laptop from damages by lightning/etc. Unless there's any better ideas that are cheap)
In response to Moonlight Memento
I would still be moving everything you care about off of that drive. It might still be failing. Do the hardware diagnostics still complain?
In response to Jp
Going to be running it again soon. Things were backed up previously, anyway, so nothing is really wrong in that regard.

Going to be running a defrag now - I'm able to now.