No bootable device" error? Help!

So, I picked up a used Dell Inspiron 15 recently and got Windows 10 all set up on it.
But here’s the kicker—every thirty minutes or so while I'm actually trying to get things done, the screen just goes pitch black
and hits me with this message:
"Broadcom UNDI PXE-2.l vl5.0.11
Copyright (C) 2000-2011 Broadcom corporation
Copyright (C) 1997-2000 Intel Corporation
All rights reserved.
PXE-E61: Media test failure, check cable
PXE-MOF: Exiting Broadcom PXE ROM.
No bootable device — insert boot disk and press any key"

I already tried a complete clean install by formatting the partition entirely, thinking that might smooth things over, but nope—same headache every single time.
Does anyone have a clue what might be causing this little hiccup?

PXE lets you install an OS over the network instead of messing with USBs or DVDs.

Since you said this happens while you're actually using it, does that mean the laptop just restarts on its own and kicks back to the boot menu...?

If it's rebooting randomly and can't find any media or even the hard drive where Windows lives, you might be looking at a dead drive or a loose connection to the motherboard.

But let's not jump to the worst-case scenario just yet... try going into your boot list and disabling network boot. Make sure Windows Boot Manager is set as the top priority so you can see if it actually recognizes the drive or just keeps skipping down the list.

Also, if you're running in legacy mode, give UEFI a shot.

Honestly, I don't think this guy actually knows what he's talking about... I mean, you won't find an error message like that anywhere online—it's basically just something that pops up during the boot sequence and then vanishes...

Nancy Thompson8 said:So, I picked up a used Dell Inspiron 15 recently and got Windows 10 all set up on it.
But here’s the kicker—every thirty minutes or so while I'm actually trying to get things done, the screen just goes pitch black
and hits me with this message:
"Broadcom UNDI PXE-2.l vl5.0.11
Copyright (C) 2000-2011 Broadcom corporation
Copyright (C) 1997-2000 Intel Corporation
All rights reserved.
PXE-E61: Media test failure, check cable
PXE-MOF: Exiting Broadcom PXE ROM.
No bootable device — insert boot disk and press any key"

I already tried a complete clean install by formatting the partition entirely, thinking that might smooth things over, but nope—same headache every single time.
Does anyone have a clue what might be causing this little hiccup?

Honestly, you don't need to bother installing anything else right now.

Just pop those RAM sticks out of their slots, give them a little spray with some WD-40 to clean things up, and click them back into place.

If that doesn't do the trick and the issue pops up again, just let me know.

Just to clear things up, PXE isn't really for installing stuff—it’s for booting over the network when you don't have any local bootable drives handy, whether those are physical sticks or software-based. That said, you *can* use it to install an OS on local machines, boot up zero clients or thin clients, or even give a little nudge to a "fat" client during startup.

From what you're describing, it sounds like your locally installed OS is occasionally losing its connection and timing out with its primary boot device (most likely your C: drive or the hard drive). Your BIOS probably has a boot order set up something like C:/HDD/SATA, then DVD/SATA, and finally PXE.

If that SATA controller starts acting up, the OS sitting in the RAM or the BIOS just moves on to the next device on the list. Since you haven't got PXE configured, that’s why you’re seeing that message—honestly, if you actually had something connected to the network card, you'd probably be stuck waiting for a full minute!

Here’s a theory: the SATA controller (or maybe just the hard drive itself) fails, and the OS tries to write a Blue Screen of Death dump file. But then it realizes there's nowhere to save it because the hard drive is MIA or the SATA controller isn't responding. So, it just resets and tries to boot from the next available thing on the list, which happens to be PXE (since the DVD drive is also unreachable due to that same SATA/AHCI glitch).

===========

Go into your BIOS and strip away every single boot option except for C:/HDD/SATA.

Once the crash happens again, you can be pretty certain the issue lies with the SATA/AHCI interface or the controller itself—basically, the motherboard. To test this, grab a DVD drive and a bootable disc. If you can boot from the disc and everything works fine, but the hard drive still won't budge, then you've definitely found the culprit: the motherboard or its built-in SATA/AHCI controller.

Also, it’s totally possible that the RAM modules are the real headache, just like our buddy mentioned. Try cleaning the contacts first, but if the crashing keeps happening, swap the modules out (or try running on just one at a time since you've probably got two) and see if that fixes it.

It’s actually kind of wild, but my laptop has been running non-stop for over six hours now without that dreaded black screen popping up again

Like I said before, it could totally be a faulty HDD or just a bad connection... then during boot, the system misses it and just moves down the priority list. You can always pull an OS install via PXE if you've got a server to grab it from.

@Sexbot: Just pull the RAM sticks out of the slots, spray them down with some WD-40, and shove them back in.

NEVER do that. You're way better off just cleaning them with a standard school eraser instead of coating them in grease.🤦

wearymason4 said:@Sexbot: Just pull the RAM sticks out of the slots, spray them down with some WD-40, and shove them back in.

NEVER do that. You're way better off just cleaning them with a standard school eraser instead of coating them in grease.🤦

Yeah...

wearymason4 said:@Sexbot: Just pull the RAM sticks out of the slots, spray them down with some WD-40, and shove them back in.

NEVER do that. You're way better off just cleaning them with a standard school eraser instead of coating them in grease.🤦

I actually find WD-40 to be an excellent cleaner for metal surfaces because of its specific acidic composition, regardless of that slight oily residue it leaves behind. In fact, I've been using it as my go-to tool for cleaning up contacts and cables in electronics for about eight years now. Whether I'm working on tablets, desktop PCs, or even those tricky LVDS cables in modern TVs, the results have been surprisingly great every single time.

It's just a fact of life, though I know some folks here might find it pretty hard to move past their old-school prejudices.

Look, WD-40 is meant for heavy machinery, not delicate electronics. If it were actually designed for circuits, we wouldn't even need specialized contact cleaners and stuff like that... Most of those products are oil-based anyway. Why bother messing around when you can just get great results using a solid, dry rubber tip?

...the instructions for WD-40 basically say it leaves a protective coating behind once you're done... I mean, there's really nothing else to add to that

Using WD-40 on electronics is probably going to cause way more problems than it actually solves. You should probably stick to using a dedicated contact spray, whether you need the dry or wet kind.

You really gotta watch what you're doing when cleaning electrical contacts.

There are tons of different types of electrical contacts out there.

The basics? You've got low-frequency versus high-frequency. Then you've got the whole breakdown of high current vs. low current, high voltage vs. low voltage, and so on and so forth.

Memory modules run on crazy high frequencies with super low voltage and current. Their contacts are just as critical as the ones on your CPU. When we're talking about a typical 2GHz setup, that contact needs to be absolutely flawless from both a mechanical and chemical standpoint—perfectly smooth, zero oxidation, no electromigration, no gunk, nothing. Whatever "perfect" means in this context.

WD-40 is basically an acid that eats away at the surface (which is usually already compromised anyway). How much damage it does depends on the chemistry of the surface you're hitting. At the end of the day, even if it manages to strip away all the oxides, carbides, nitrides, and grime, you're left with a surface that's uneven, even if it looks "super clean." Because of that roughness, you're looking at extreme electrical stress, oxidation, burning, and performance degradation due to increased resistance. You can even end up generating a massive amount of RF interference because those contact surfaces start sparking while they burn. You won't be able to measure that RF noise easily, but trust me on this—it shows up crystal clear on an oscilloscope. We're talking transient contact noise. Every electronic device or contact has to have some kind of "smart" mechanism to minimize and neutralize that stuff to a certain degree; otherwise, instead of getting a crisp digital signal (not to mention the usual headache of digital signal distortion in an analog world, but that's a whole other story), you get a giant, uncontrolled mess called noise. Figuring out how to fight that noise and pull a useful signal out of it is a massive engineering hurdle. As frequencies go up, which forces voltages and currents down, the electrical charges shift, making the noise way more pronounced and the demand for perfect contacts even higher. (And yeah, there's also basic thermal noise, but let's not get sidetracked.)

Isopropyl alcohol is probably the gentlest stuff that can actually clear up most contact interference. It's actually the main ingredient in most "contact sprays." Once everything dries, you should blow it all off with some ultra-clean filtered air. And I mean it: NO Q-tips, no paper, no cheap shop compressor air. And definitely no erasers.

There is NO paste or oil that can replace direct metal-to-metal contact. Sure, it might work for a tiny bit of time, but in the long run, they're going to start burning, which causes way more harm than good.

If you've already messed with high-frequency contacts using something like WD-40, the first thing you need to do is kill the power immediately and thoroughly degrease those contacts:
- First, use some heated medical-grade naphtha, wait for it to dry completely, then blast it with clean air.
- Then hit it with isopropyl alcohol. Then blast it with air again.

George Murphy12 said:Like I said before, it could totally be a faulty HDD or just a bad connection... then during boot, the system misses it and just moves down the priority list. You can always pull an OS install via PXE if you've got a server to grab it from.

Nope.

PXE is strictly just a network communication protocol. Seriously, you could have a rig with zero hard drives, no DVD drive, no smartcards, no microSD, no permanent storage at all—just raw RAM and an EPROM that supports PXE—and the PXE will boot that machine up every single time and everything will run just fine.

A PXE server is basically just a machine that spits out a boot image over the network to a PXE client, usually using multicast ethernet. At its core, a PXE server is just a glorified file server running a slightly different protocol. That PXE boot file? It’s literally just a plain old file (you just gotta know how to prep it) sitting on a file server. Think of it as being super similar to a TFTP server.

What actually happens once the client boots that "dumb" boot image over the network is a whole different ballgame.

Jack Cook7 said:Nope.

PXE is strictly just a network communication protocol. Seriously, you could have a rig with zero hard drives, no DVD drive, no smartcards, no microSD, no permanent storage at all—just raw RAM and an EPROM that supports PXE—and the PXE will boot that machine up every single time and everything will run just fine.

A PXE server is basically just a machine that spits out a boot image over the network to a PXE client, usually using multicast ethernet. At its core, a PXE server is just a glorified file server running a slightly different protocol. That PXE boot file? It’s literally just a plain old file (you just gotta know how to prep it) sitting on a file server. Think of it as being super similar to a TFTP server.

What actually happens once the client boots that "dumb" boot image over the network is a whole different ballgame.

Obviously you can boot from it, that's what it's for. But who actually cares about using this at home when you've got an HDD and everything stays right there on it? In a big corporate office, though, it's way easier to use PXE to load a custom OS image with all your scripts and software pre-loaded. It beats rebuilding a USB stick or manually tweaking a fresh OS install every time you change one little thing...

So, we're both right, but that still doesn't help the guy above us fix his mess. Like I said, he just needs to pull it from the boot list and make sure Windows is set to first priority. People always leave things messed up—sometimes they leave USB boot as the priority because they installed something and now every time they plug in a thumb drive, the machine tries to boot from it... unbelievable...

Look, I’m not trying to drag this out, so yeah, I’m with you on that.

Just have them jump into the BIOS and yank PXE right off the boot list, then we'll see what kind of magic happens.