To turn on the display and release the lock, just press on the left most hardware button (first button) and the right most hardware button (forth button) simultaneously. Only these two buttons are pressed down together can unlock your PPC.

Installation:
Just download the zip file and copy the ScreenLock.cab file to your PPC, and click on it with any file explorer. It'll be installed under \Program Files\ScreenLock. Or you can choose to install it on an external card.

ScreenLock only takes about 7KB space. It should work on all PPCs with ARM (including XScale) CPUs.

Update Description:
v1.2:
- PPC 2002 support added.

v1.1:
- Record button locked even it is assigned to "record" program.

***** [Jul 26, 2008] by Wodarek using Fujitsu Siemens Pocket Loox 720
Thank you! This is very useful program.

***** [May 1, 2008] by Abner Famoso using Dopod 818 pro
Cool... I thought it won't work in my phone... after trying other lock apps... I re-installed it ScreenLock again.. and it works now... just read other reviews...

***** [Apr 18, 2008] by Gav using HP iPaq h6365
Excellent program! For all those wanting to know which buttons to press click on start button, go into your "Settings" and then click on "Buttons", here you will see each button numbered. From memory I think I had to press them in reverse order (ie, hold down button 4, press button 1, then release button 4). Has anyone tried this on WM5? I've just upgraded to a o2 xda flame.

***** [Dec 8, 2007] by Jaxplanet using AT&T Tilt HTC Kaiser
Excellent Application! Internet Explorer + OK (The one on the front not the side.) I found out just buy going to Settings > Buttons. It shows the button's number and an icon that matches your PPC's physical button labels. Just press 1 and 4 at the same time. No holding down or pressing one or the other first.

***** [Dec 4, 2007] by Felipe Garan using Ipaq H6314
The unlock bottons are in this order to press, camera (hold) first and contacts press and relaease all. And was unlocked again.

*** [Jun 18, 2007] by zoemer using E-ten M700 WM6
Just like some other people here, I had big difficulty in finding the right way to unlock it again. But after a lot of trying, I figured out that the trick is to *first* press and hold key 4 (in my case the record button), and *then* press key 1 (in my case the camera button). If you try any other combination or order of hitting buttons (i.e. first 1 and then 4 will), it will not work. I only figured this out after several soft resets. And, as others already mentioned, I really miss a feature to change the key combination. And I would like to be able to use something else than two keys; for example, I would like to be able to unlock my device by hitting the third button (the home button) three times in one second. Would love that.

** [Jan 1, 2007] by Forrest Run using Dopod 818pro
When the screen locked, I can NOT unlock the screen again! Even I press the up-left-key + up-right-key. At last, I had to soft reset...

***** [Dec 4, 2006] by Seltzer using SPVM2000
Excellent utility! Thanks a million for making it freely available.

***** [Nov 20, 2006] by Karpak using I-Mate Jasjar
Good tool, Initialy faced problem in finding the key 1 and 4 it is Contact Button and Voice Record button. Just now tried, I hope it will be good to use.

** [Oct 16, 2006] by legacye using Orange SPVM2000
Installed the app, loaded it up, and once the screen went blank, no combination of the 4 main hardware buttons, the top 2, or the side shortcuts would get the screen to come back on fully. A brief view of the screen is presented for about 0.5 seconds when pressing the buttons suggested in previous posts, but this returns to black a moment later. Soft Reset required :(

** [Aug 2, 2006] by pdenker using Cingular 8125
Blanks the screen but doesn't lock any button. Messaging-VoiceRecord to unblank. Cingular 8125 running AE Button Plus (which might be what causes the buttons not to lock; don't know).

***** [Jun 9, 2006] by mypansat using Navman PIN100
Program works great. My Navman Pin100 unlock combo is the Notes and Task keys (top two buttons on the face). Thanks!

**** [May 3, 2006] by Alexey Demchenko using HP iPAQ 6340
To: Edwin using IPAQ 6340. It works very well. Unblock keys are "Contacts" and "iPAQ Wireless" as default.

***** [Mar 29, 2006] by Suforcent using Qtek 2020
What a wonderful program, thx! In Qtek 2020 the buttons are the up right button "calendar" and the that "recorder" button on the left side up.

** [Mar 17, 2006] by Mark using Axim X30
Turns off screen only after I run it a second time. Then it doesn't even lock the program buttons. Pressing the power button turns the display back on then I'm left with the results of any button presses. Button 1 + 4 combination does not do anything. Probably just a device specific problem, but it would have been nice if this had worked.

* [Mar 1, 2006] by RockyPilot using PPC-6700
I have the PPC-6700. Buttons 1 and 4 are the factory defaults of “e” (located on the side) and “Win” (just to the left of the joy stick). I came to the same conclusion as everyone else. I could not get it to come back to life without having to do a restart.

* [Feb 10, 2006] by MooreSoccer using XV6700
Don't waste your time. Exactely the same result as PPC6700 could not unlock. I had to soft reset.

***** [Feb 1, 2006] by Walter using Qtek9100, MDA Vario
Works! buttons are message + voice dial (top-left-front and top-right-side). Just push both buttons simultaneous.

***** [Jan 23, 2006] by Rooster using Ppc 6700
Cant seem to find the right button combo. Im running windows mobile 5 so maby its not compatible?

** [Jan 23, 2006] by michael using ppc 6700
Dont even waste you time for the ppc-6700, install ok, launches ok, try and onlock it... impossible, i had to soft boot to gain control...

***** [Jan 9, 2006] by Jacol using HP iPAQ 6315
Simple but very useful thing! And it's freeware! On my iPAQ 6315 it works without any porblems. THANK'S!

* [Nov 28, 2005] by Pelle using iPaq 6340
Rave reviews but how do I do to install it? There's 2 files in the zip and none of them are executable on my PPC...

***** [Sep 19, 2005] by Tim using O2 XDAII mini
Exactly what I was after. Unlock button combo is Record+Calendar.

**** [Aug 22, 2005] by booedoffstage using HP iPAQ 6365
Just what I was looking for - though, it took a while to figure out the key combo to unlock; which happen to be for my 6365 - 1) press and hold camera button, 2) press contacts button, 3) release both buttons. Great utility even lets me receive incoming phone calls! Interestingly, when "locked", if you press the green phone button, it opens the phone application in the background, but fortunately doesn't seem to make any outgoing calls.

***** [Jul 20, 2005] by Eve using MDA III
This has really solved my problems although it took me a while to unzip the screen lock before it could work on my PDA. It took me a while to figure out how to unlock it. To unlock you have to press the calender button and mail button to unlock it. Thanks for this wonderful tool.

***** [Jun 13, 2005] by Matt using Eten M500
Does what it says on the tin! - for M500 keys are the camera button + the record button. (the two buttons on the left side)

*** [Jun 1, 2005] by Paul using Samsung i700
AHHHHHHHH. Samsung i700 does not designate a #4 button so I cannot use this app. I need a program like this so the search continues. Designating buttons would have enable me to use the app.

**** [Jun 1, 2005] by Leif Harmsen using iPAQ 4150 PPC2003 Aug2004 ROM update
Great utility with one problem. Sometimes when I try to unlock it enters a relock loop, so my screen just flashes and is locked again and I need to reset the whole PDA to get control again. I'm not sure why this happens, but it happens when there's an alarm or alert for sure. Most times it works perfectly.

***** [Jun 1, 2005] by Kyle using I love it
It works perfectly. It does exactly what I want it to do.

***** [Jun 1, 2005] by Mark Snow using Audiovox PPC 6600 (Verizon XV6600)
I agree completely with 'Qtek 9090' review! For me as well - it was the Calendar and the Messaging keys.

**** [May 27, 2005] by Mark Stephan using I-Mate PDA2k
Like all the other reviews, just what I have been waiting for. Again, assigning of buttons would be good, but for my PDA2k it is the Calendar button and Message button. Buttons 1&4

***** [May 20, 2005] by JG using Qtek 9090
On Qtek 9090 and XDA III the two buttons are mail+calendar. It works. Suggestions:
- add menu item for quick usage
- add config so that one can change keys
- add password and autolock in certain time
- make it shareware after adding this and you'll get rich...

***** [May 9, 2005] by Denise using sprint/audiovox ppc-6600
I love it! Had to find the correct buttons to unlock it. They are buttons number 2 & 4.

***** [May 4, 2005] by Salim using spv m2000
Greate utility, thanks.

***** [Apr 15, 2005] by Kentopolis using Dell Axim X30
This is a great little utility. Had a problem at first figuring out which were the two buttons, on my Axim X30, it ended up being the notes button (furthest left) and my mail key, it only took a few rounds of clicking buttons to figure it out, it will be nice to carry my ppc in my pocket and not have everything turn on!

**** [Apr 13, 2005] by skruger using iMate PDA2K
Very usefull program. Indispensible to turn your PDA into an MP3 player. Great work!

***** [Apr 6, 2005] by Kalel Steel using MDA III
This lock works great if you want to leave your GPRS connection active when your on AOL or Yahoo. I like my GPRS network connection to always stay active unless I turn the phone on. It is possible with this program. When you down load it and open it assign this program to a button like calendar. This way you can lock the device; now to open it all you have to do is press the button you assigned it to plus the mail button which is left of the "E" Internet Explorer button.

***** [Mar 30, 2005] by 6630 using Siemens SX66 PPC
I think this is a very nice application, so far, but I had to search for the Key combination referred to in the instructions. The best way to find the button combo for your device is to go to the Button Application; Start--> Settings--> Buttons. This will display "Button 1" and "Button 4". This is the Unlock Combo for your device. Would be much better if I could assign my own Unlock Key Combination. Good Luck!

***** [Mar 23, 2005] by fjendel using MDA III
ScreenLock works fine on the MDA III... I didn't find the 2 buttons, but you can reactivate your MDA by pressing the power button and quickly pres the "x" on the right side on your display. So ScreenLock will exit and your keys are unlocked! The only problem is that you need both hands to reactivate your device ;)

*** [Feb 21, 2005] by Thorsten using XDA
Lock works, nice thing. But I couldn´t find the buttons to unlock my XDA -> soft reset ;)

**** [Feb 21, 2005] by DJ Radon using XV6600
Works fine on XV6600 (PPC2003SE) in landscape mode although, as another reviewer mentioned, the phone keys still work. The unlock keys are calendar (upper right) and mail (2nd from left, above d-pad).

***** [Feb 11, 2005] by Kiwilegal using Loox 720
Great utility. Need to get the knack on how to press the two buttons together. For a while, I thought I could not turn my screen on again.

**** [Feb 2, 2005] by Ken Wagnitz using Loox 720
Seems to work OK. On the Loox720, press the top-left (calendar) and bottom-right (home) buttons simultaneously -ie not one first then the other. Disadvantage is that the jog wheel is no longer available as a volume control.

* [Jan 21, 2005] by Wolfgang Meier using HTC "Blue Angel"
Locks all buttons except phone buttons which open and operate(!) the phone while the screen stays black.

*** [Jan 19, 2005] by Edwin using IPAQ 6340
Concept is great but be aware this does not work on most Smartphones on Windows Pocket PC 2003 Phone Edition (you can lock but you cannot unlock...)

***** [Jan 10, 2005] by Ender using HP iPAQ 1910
Great work! Now that I have it, couldn't imagine living without it :)

***** [Dec 22, 2004] by Art Jones using iPAC
Yeah Baby ! Just what I needed to save battery power while music plays... great program ! Thanks.

** [Dec 13, 2004] by Martin using MDA III
It seems to lock alright, but how am I gonna find out what the "right most and left most hardware button" on my particular device are? Couldn't find them, couldn't unlock. Soft reset. Ugh. Documentation!!!!!

***** [Jul 23, 2004] by Scythe using Dell Axim X5
I've been wating for a program like this for ages. Eerytime I listen to music and put my PPC in my pocket, some button always gets pressed. Thanks a lot for this piece of software. Nice work!!