[Windows 8 Development and Hacking] young blade:
Dear XDA friends :laugh:today I make available an guide to align/calibrate the touch screen with more than just 4 points.

The benefit of aligning the screen with more than just more than 4 points is that the touch screen will be more acurate

when there is an touch input.

After much frustration of my 22" touch panel not registering my touch inputs the way it should I've spend weeks to search the internet

for an solution to this problem.

And the problem lies in the fact that microsofts calibration tool offers too few calibration points (4 or a few more for pen input).

This guide also applies to pen inputs but when using a pen you should keep in mind that the first point you touch while calibrating has to be with the pen.

Before starting off you should make an windows restore point. okay lets get it started.

1) Go to the control panel and open tablet pc settings.

2) Hit reset.

3) Open command prompt CMD as administrator.

4) Choose one of the following options: 4a,4b or 4c:

4a) As mine touchscreen is 22" 1680x1050 I calculated the folowing line to get 150 calibration touch points:

tabcal lincal novalidate XGridPts=5,117,229,341,453,565,667,789,901,1013,1125,1237,1349,1461,1537,1675 YGridPts=5,109,213,317,421,525,629,733,837,941,1045

Copy and paste this line above into the command prompt and hit enter than proceed to step 5.

4b) If your screen resolution is 1280x800 and you want 36 calibration see the following line:

tabcal lincal novalidate XGridPts=5,259,513,767,1021,1275 YGridPts=5,163,321,479,637,795

Copy and paste this line above into the command prompt and hit enter than proceed to step 5.

4c) If you have a different screen resolution than the ones above than calculate the best entries for your screen:

lets say you want 36 calibration points for your 1280x720 screen reslotution.

than do the folowing for the XGridPts: 1280-10= 1270

Now we make sure that we start of at XGridPts=5 and the last XGridPts=1275

that leaves us with 1270 Pts lets divide it by 5 > 1270/5= 254

So the steps will be 254Pts

As our first XGridPts=5 we keep adding 254Pts until we get around 1275Pts

So 5Pts+254Pts=259Pts and that will be our second Pts

The result will be: XGridPts=5,259,513,767,1021,1275

Next will be our YGrid:

720-10=710

Now we make sure that we start of at YGridPts=5 and the last YGridPts=715

that leaves us with 710 Pts lets divide it by 5 > 710/5= 142

So the steps will be 142Pts

As our first YGridPts=5 we keep adding 142Pts until we get around 715Pts

So 5Pts+142Pts=147Pts and that will be our second Pts

The result will be: YGridPts=5,147,289,431,573,715

So now we have succesfuly calculated the x and y grid:

XGridPts=5,259,513,767,1021,1275 YGridPts=5,147,289,431,573,715

Copy and paste this line above into the command prompt and hit enter than proceed to step 5.

5) If al goes wel you should now be presented with an calibration window with more than 4 points hit all the points and your touchscreen should be

beter to use in older applications.

if you get any syntax error make sure there are no spaces in the numbers while copy and pasting.

6) If you get an pop up message when using 4a 4b or 4c saying that there already are calibrations settings entered and that you should go

to the tablet pc settings and hit reset you should do the following:

*Go to Control Panel>Device manager

*In Device Manager, locate the device you want to remove/reset, and then double-click the device name.

*Click the Driver tab, and then click uninstall and disconnect the device from computer and restart.

Now when you reconnect the device after the restart it should reinstall the default driver settings.

Of course you should use these settings at your own risk but it shouldnt be a problem if you made an restore point.

As an result my touchscreen works 100% in every part of the screen.

If you have used this guide please let me know your results and dont forget my thanks meter :).

Sources used:

http://forum.tabletpcreview.com/ep121-slate/43622-pen-calibration-trick.html

http://answers.microsoft.com/en-us/windows/forum/windows_vista-hardware/tablet-calibration/f11fcc78-2926-4463-8445-ec6e7de2603d