I'm running Win 7 RC on 2 machines (different motherboards, processors etc). Both machines are joined to domains and work perfectly except for one small issue.On both machines, there are times when I unlock the machine and after unlocking the screen goes blank and doesn't show anything, and the only thing I can do is reboot the PC. This doesn't happen every time I unlock the machine, only some times (I would guess 1 in 10), but as you can imagine, when it does happen it's very frustrating and annoying.Has anyone got any idea what's causing the problem and what I can do to stop it happening?ThanksPhil_C

Phil - Sounds like your machine went into sleep mode and the video card never quite woke up. It seems to be a common enough issue. Make sure you've got the latest drivers for your video card. Beyond that, the only known way to avoid this issue is to disable sleep/standby/hibernation. The programmers are aware of the issue and should be working on a fix.

Hi Wolfie2k6Thanks for your thoughts - the only way that I can see of turning off Sleep mode is under Power Options in Control Panel. I've already changed the power settings to performance and set the monitor and computer to never turn off. Is there anything else I can do?If this is what you mean, I've already disabled sleep and the problem's still there. I've got a password set to activate after 5 minutes of inactivity, and it's after this has kicked in that I occasionally get my problem.ThanksPhil_CPS - The video's on the motherboard (Gigabyte MA78GPM-DS2H) and it's got all the latest ATI Radeon drivers.

Hello Phil,Was this ever a problem on your previous operating system?

Been away a few days - come back and the machine wakes up perfectly - leave desk for an hour or so, come back, try to unlock it and screen goes blank!The machine is brand new, and the 1st O/S on it is W7RC, so I don't know the answer to above question.I have another machine that's running W7RC - that works perfectly - it's just this one machine that has this issue.Phil C

Having got really frustrated earlier about this, I've now calmed down a little and waited. I've found that when the screen goes blank, if I wait for a period of time, the screen does come back. It can, however, be anything from immediately to a minute or longer, but there's no rhyme or reason about how long it takes. I can have loads of applications open and it comes back immediately, I can have loads of applications open and it takes ages, I can have no applications open and it takes ages.It's almost as though the machine's goine in to hibernation, but in the power settings I've turned off hibernation, sleep, the hard disk never stops spinning etc. etc. etc., but it still happens.I've tried upgrading my video drivers and they're the latest, so I'm getting really baffled.Any help would be appreciated.ThanksPhil C

Hello Phil,What is the exact driver version you are running? In most cases I have had better functionality with the default WDDM 1.1 driver that installed with Windows 7 than the most recent manufacturer's version. Especially with on-board graphics.-Scott

Hi ScottThe driver for theATI Radeon HD 3200 on board graphics is v8.612.0.0, dated 28th April 2009.PhilPS - I came in this morning - the machine has been sitting idle all over the weekend, and it's worked perfectly all morning.

Hello Phil_C,Were any updates installed during the weekend while it was sitting? Also is it still working perfectly?-Scott

Hi ScottNo, no updates were installed over the weekend.I think that this is a glitch between W7 and the driver, so will just have to live with it until ATI produce a dedicated W7 driver. For this week, it's worked perfectly apart from once locking up, so I'll live with it until the full release.Thanks for your help - it's been appreciated.Phil_C

Phil_C,There is a driver dated 6/15 on the ATI website.

Hello Phil_C,I suspect you are right this is a driver issue probably with either your video card or ACPI drivers and will probably be sorted out by the final release. ACPI drivers is a well known bug at this point.-Scott

Hi, we are using RTM Win7 on Dell E6400 laptops (nvidia)... and we have this issue as well, so I dont think it is video driver related perhaps just a Win7 bug. Very intermittent like 1 / 100 but a real pain when it happens!

I, too, am having this issue. I am using a Dell OptiPlex 755, Intel Core 2 Duo, Windows 7 Enterprise 64-bit. I can't check my video adapter model, as my machine is currently hung in the Black Screen abyss. This happens intermittently, and does not seem to be related to which applications I am running when I lock the system (I originally suspected VMware Workstation to be the culprit, but it happened after a rebuild, before I installed VMware Workstation). I am able to RDP to the machine from my MacBook, but when logging in as a different local administrator, Win 7 waits a rather long time for my active session to respond to a dialog (which I can't see) before taking over the active session and locking the console. I have had this with the beta, RC, and now general release of Win 7; Vista didn't have this issue. My video adapter is an ATI, and I have experienced this issue with both the bundled driver that comes with Win 7, and the Win 7-specific driver from their Web site. This is now occurring daily for me.

I too am having this issue, but it seems that this only happens with the default Windows 7 theme applied. If I apply a different theme, the problem does not appear.

We've been having this issue on several machines for several months now. We've tried several "solutions" such as changing power settings, changing virtual memory settings, re-installing video drivers, changing users/groups configurations, clearing out all event logs, disabling event logging, changing UAC settings, and changing monitor settings (we all have dual-monitors). Nothing has worked so far. Curiously, sometimes someone might go days without a black screen even though they lock their computer several times a day, then suddenly the problem will crop up again and they'll get a black screen as often as 1 out of every 2 times. Sometimes the problem goes away after one of the "solutions" or sometimes it happens on its own. We had one guy who got a new Win7 machine about a month ago and did not get a single black screen until just yesterday. Sometimes it seems like if you jiggle the mouse prior to unlocking that you have less of a chance of getting a black screen. Lately this hasn't worked as well. Sometimes we can get the screen to come back after moving the mouse around a lot, activating sticky keys, pressing ctrl+alt+delete and/or ctrl+shift+esc and/or Win+L, then leaving the computer sitting there for a while till the screen comes back. Other times, depending on how important it is to have whatever we previously had open, we just restart, since this usually takes less time than waiting for the screen to come back. It's also just as likely to come up when you lock the computer for a few minutes as it is when you lock it overnight. Other peculiarities I've noticed: if you have music playing, you will still hear music for a good 5-10 seconds after the black screen comes up. The music then quits. I've checked event viewer (when I had it enabled) and there are no particular events that occur prior to or during the black screen. Sometimes when getting the screen to come back after a black screen, after hitting "cancel" (from the screen after hitting ctrl-alt-delete), there's a second black screen, though this one only lasts 5 seconds. Everyone who's used Windows 7 here has liked it a lot, but this issue really puts a dampener on whole experience. We have a company policy of locking our computers whenever we step away, even for a few seconds, so this severally hinders our ability to comply with this policy. This issue would almost make it worth going back to Windows XP, if not for the fact that the reboot happens lightning fast.

Thanks, 'ResumeNothing', that was very in depth and helpful. I've been pulling my hair out trying to fix this one. I've got the same issue as all of you, here's my setup: 5 computers in our Engineering Dept (all on same domain, mainly running SolidWorks 2010 SP 2.0 all day) 4 are Dell T3400 with the exact nVidia cards and exact software. 1 is an HP xw4600 with a different nVidia card than the others. Two of the Dell's have this lock black screen, and the HP also gets it. What we all need to figure out here is our common software/hardware/setups. I'm fairly certain it's not hardware since all of us are differing in that area. My problem PC's have these things in common: Dual monitors Running Solidworks 2010 SP2.0 Running Outlook 2007 Running Windows 7 64-bit Running Winamp Same local domain, same networked drives Running Desktop Authority The hardware differs slightly as defined above. Please respond if any of your computers match my setup.

I am having the same problem, with a 4 month old Dell Optiplex. Anxiously awaiting any fix suggestions for this as well ...

I am having the same issue, with 1.5 year old dell precision m6300. Windows XP Windows 32. NVidia Quadro FX 1600M.. Another anxiously awaiting any fix suggestions. Cheers

Hey 'Manufacturing', Just wanted to pipe in on here, even though your post is almost 5 months old. I've been dealing with this for a long time as well. I share only 2 of characteristics you have. Maybe this can help us narrow it down. 1. Dual Monitors. 2. On a domain. Other than that, I'm running Outlook 2010, and Windows 7 32-bit. I am on an HP Compaq 6000 Pro Microtower. 4GB RAM, Intel Core 2 Quad-core Q9400 CPU @ 2.66GHz I have another co-worker who does not have this problem, who has an identical computer and set up that I have. Only difference between ours is that he is running Windows 7 64-bit. Another difference I just thought of between my computer and my co-worker's, that in the past wouldn't really have any merit, is that we have different monitors. Both of us use dual-monitors. But I'm using Acer X223W monitors and he's using HP LE2201w monitors. Normally, in the past, windows doesn't give a damn, but in Windows 7 it will auto-detect the model and adjust it's resolution accordingly. It's much more involved with the monitor than in OS's past. Do you think this could have anything to do with it??

Guys, I think we can safely conclude that there are only 2 commons in this issue: 1. Dual monitors 2. Windows 7 Around here, we have 3 Dell Precision Workstations, 2 with Samsung monitors and one with Dell monitors. Out of these three, two show the symptoms. Other than you might expect it is one of the Samsung setups and the Dell Setup. Off course we have tried different driver versions (OEM and Nvidia) but nothing seems to help. Also the problem is not quite persistent, it happens anywhere from once a week to multiple times in one day. Anyone out there that has found a solution?

Hi. In last month I did reboot computer about five times because of this black screen of death. It happens sometimes and immediately after unlocking my work PC. So symptoms are very similar to symptoms described in this post. I have Windows 7 64-bit installed on ASUS P5QC with Dual-Core Intel Pentium E6500 4GB RAM and NVIDIA GeForce 6200 LE on single monitor.

+ it seems that the postponed system restart after applying new windows updates may cause this.

This issue has been plaguing my several Windows 7 x64 machines ever since I switched to it early this year. I seem to have finally tracked it down to being somehow related to having network drives mapped, after seeing that mentioned in another forum thread. About a week and a half ago I setup a couple of scheduled tasks to unmap and remap the network drives in question in response to the workstation lock and unlock events, with a short (5s) delay on the latter. Thankfully this seems to have done the trick; I haven't seen the problem since. This still doesn't explain why it's affected several machines of mine but not those of my colleagues, as far as I'm aware, so I guess there's still some configuration issue that's exacerbating it, though their setups should be mostly identical.

I have a brand new Alienware computer at work and this same issue is causing me to hardboot each time it happens. Others around me are not having the same issue, although their Alienware computers are a few months older.

Sounds like an interesting solution. Can you elaborate on the implementation? How do I make actions on lock/unlock events?

I'm running Win 7 RC on 2 machines (different motherboards, processors etc). Both machines are joined to domains and work perfectly except for one small issue. On both machines, there are times when I unlock the machine and after unlocking the screen goes blank and doesn't show anything, and the only thing I can do is reboot the PC. This doesn't happen every time I unlock the machine, only some times (I would guess 1 in 10), but as you can imagine, when it does happen it's very frustrating and annoying. Has anyone got any idea what's causing the problem and what I can do to stop it happening? Thanks Phil_C Apparently this is a known issue: http://support.microsoft.com/kb/2431700 Updating graphic drivers or disabling Aero are solutions described in the article. Thanks