"assuming you can contend with pure C"

Not yet... ;-( but thank you very much for this insight, I'll try to make that sense out of it my very limited means for now will allow for!

"I am trying to avoid adding any extra software to my Netbook"

It's the intro of my tutorial that will interest you, then ("it's a macro tool, AND a text expander!") and the fact that indeed, AHK is very lightweight, it will NOT slow down your netbook. I have edited my tutorial for some more hours, and it's become even longer than before, but everything any starter needs for AHK is there now (I hope), and in succinct form (here, you are free to laugh out loud). Tell me if anything isn't 100 p.c. evident, I'll revise anew. And get rid of 180 of your 240 applications and tools to make room for some breathing! (As for AHK, it could perfectly live with all this presumed crap there I suppose ("crap" = not speaking of the some 25 p.c. good and very good things that are among them I'm sure).

It's the intro of my tutorial that will interest you, then ("it's a macro tool, AND a text expander!") and the fact that indeed, AHK is very lightweight, it will NOT slow down your netbook. I have edited my tutorial for some more hours, and it's become even longer than before, but everything any starter needs for AHK is there now (I hope), and in succinct form (here, you are free to laugh out loud). Tell me if anything isn't 100 p.c. evident, I'll revise anew. And get rid of 180 of your 240 applications and tools to make room for some breathing! (As for AHK, it could perfectly live with all this presumed crap there I suppose ("crap" = not speaking of the some 25 p.c. good and very good things that are among them I'm sure).

I have looked at your tutorial and for several months I have been making frequent visits to the AHK forum.

AHK, or come to that any programming language is something my mind cannot grasp, I simply do not think in that way.
I have put together two programs with AHK the first combining two existing scripts I found which is HERE (just updated with a better icon), the second was a modification of another existing script I found and is HERE.
As it happens they both do what they are intended to do but writing a script from scratch, at least at the sort of level required for the things I am trying to do is quite simply beyond my abilities.

As far as this thread goes I have learned a number of things that should allow me to sort it out:
The first is that the remapping of keys can easily be undone.
The second is the location of the registry key where remapping information is stored.
The third is that there is at least one existing program that appears to take account of the FN key on portables that does not need to be installed or even kept on the computer once the changes are made.
As this is registry based if there is a problem I can get back where I started with ERUNT which I run everyday on whichever computer(s) I use.

4wd,

KeyTweak is one of the programs I have downloaded, the other is SharpKeys.

When the FN key is not used HOME and END are respectively PgUp and PgDn two of the very few keys that I never use, my idea is to simply swap the second two for the first two if that is possible.

tomos,

remapkey.exe works on Windows 7 x64 without issues.

KeyTweak appeared to do the job, it recognised the mappings and created new registry keys but when I rebooted and tried the keys nothing happened, with or without the FN key, they simply appeared to have been disabled.

Works fine here, I've remapped the PgUp and PgDn keys to Home and End and it survives reboots just fine, (Win8 - which I would think would be even more anal than XP about these things).

Did you run KeyTweak after you rebooted to see if the remap was still there, (it detects any active remappings)?