Like the subject says. When I go to run the batch file, this is what I see in the output:

WeiDU v 21000 Log

Setup-HighRes.exe --nogame
[Setup-HighRes.exe] Using scripting style "BG2"

Would you like to display the readme? [Y]es [N]o

Install Component [Arcanum High Resolution Patch]?
[I]nstall, or [N]ot Install or [Q]uit?
Installing [Arcanum High Resolution Patch]

Checking version...
Copying and patching 1 file ...
[Arcanum.exe] loaded, 690176 bytes
FAILURE:
Arcanum.exe version 1.0.7.4 (English) required.
Stopping installation because of error.
ERROR: [Arcanum.exe] -> [Arcanum.exe] Patching Failed (COPY) (Failure("Arcanum.exe version 1.0.7.4 (English) required."))
Stopping installation because of error.

ERROR Installing [Arcanum High Resolution Patch], rolling back to previous state
[HighRes/Backup/0/UNSETSTR.0] SET_STRING uninstall info not found
Will uninstall 0 files for [SETUP-HIGHRES.TP2] component 0.
Uninstalled 0 files for [SETUP-HIGHRES.TP2] component 0.
ERROR: Failure("Arcanum.exe version 1.0.7.4 (English) required.")
PLEASE email the file SETUP-HIGHRES.DEBUG to drogblacktooth@hotmail.com

Install Component [Arcanum High Resolution Patch]?
[I]nstall, or [N]ot Install or [Q]uit? Saving This Log:

NOT INSTALLED DUE TO ERRORS Arcanum High Resolution Patch

WeiDU Timings
OUTER_INNER_PATCH 0.000
READ_* 0.000
DEFINE_PATCH_MACRO 0.000
DEFINE_ACTION_MACRO 0.000
INCLUDE 0.000
process_patch2 0.000
eval_pe 0.000
Parsing TP2 files 0.001
parsing .log files 0.001
PATCH_PRINT 0.002
loading files 0.002
FAIL 0.006
tp2 uninstall 0.010
COPY 0.012
Parsing TPA files 0.017
stuff not covered elsewhere 7.781
TOTAL 7.832


Obviously, since this is GOG, I am running the most recent version (1.0.7.4, and yes I double-checked), It is installed in English, and the batch file is in the same directory as my Arcanum.exe file. So... what's the deal?

Is this the first patch you're trying to install?

You haven't specified your OS or your Arcanum installation path; if you happen to be using something like Windows 7 or Vista and put it into the default Program Files folder, most patches will need to be launched with admin rights, or they won't be allowed to modify the game files.

You might want to try installing another patch first (the Unofficial Arcanum Patch, which is highly recommended since the game can get quite buggy otherwise) and see if it installs correctly under the same circumstances; if it gives an error as well, then you probably have a general access rights issue.

Arcanum patches/mods should work on GOG's version just fine, provided nothing (such as Windows UAC or anti-virus software) blocks them from replacing or altering Arcanum.exe.