OK, I feel foolish and I have a funny feeling I'm missing something obvious, but I'm at a stage where I just don't know what's going on.
I can't extract anything.
I have the latest version of the tools linked on the first page of this thread (revision 96). I copy and paste, for example, startup.vpp_pc (used to test as it's small) into the directory I keep the tools in (Q:\Steam\steamapps\common\saints row the third\GT-R96\_modding utilities). I then drag it onto Gibbed.SaintsRow3.UnpackVPP.exe which causes a dos box to pop up for about a second and then disappear. Nothing appears to happen. I tried the STR2 unpacker with a modded texture (gang_smg_high.str2_pc from the Tacticool Weapons pack) and met with identical failure. No Subdirectories are created, nothing new appears, not in that directory or in packfiles\pc\cache. Are they ending up somewhere else? Where do they appear by default?
I trawled the forums before and found things somewhere that seemed similar to this, to do with .net framework being out of date; mine is v4 and I just updated it ten minutes ago before I tried again.
I just want to edit some textures...why did volition make modding so damnably fiddly?
Thanks any and all.