Updating the OP to reflect current info (updated 5/12/2016): In 2005, Resident Evil 4 debuted as one of the most graphically impressive games of that console generation. Now, over a decade later, the visuals certainly show their age. At this point it seems safe to say that an official across-the-board HD revamp of the game isn't coming anytime soon.
Always make a backup of the files that are overwritten by the File Archive, as the original files are usually required to update the game to a newer version or to play Online!
Some No-CD/Fixed EXE files work fine in Single Player mode but are detected to be modified when trying to play online. When this happens use the original EXE to play online, else you could find yourself banned from the game!
When using Fixed Files make sure to use a Firewall which controls outgoing traffic, as some games call back to report the use of these modified files!
Some original games do not work when a certain application has been installed, like DAEMON Tools. In most cases using a No-CD or Fixed EXE will solve this problem!
Some Game Trainers are sometimes reported to be a Virus or Trojan, the most common is a keylogger called HotKeysHook or the file has been packed/protected with VMProtect or Themida and is recognized as Win32/Packed.VMProtect or Win32/Packed.Themida. In ALL cases this is a FALSE ALARM as NONE of the Game Trainers @ GCW contain known malicious code! More info in the PC Games FAQ!
If you have problems using a trainer in combination with Windows Vista, 7, 8 or 10 then make sure to run the trainer with Administrator rights and when needed in Windows XP or Windows 98 compatibility mode!
ALL available trainers are for Single Player/Offline use ONLY! Don't try to use them online else your account can/will be banned/closed!
Resident Evil 4 fans, here is something special for you today. Chris and Albert have finally released their Castle Texture Pack for Resident Evil 4. This pack features enhanced environmental textures for the entire Castle section, as well as 3D modeling and texture mapping corrections, enhancements and lighting corrections.
This pack is around 4.7GB in size and does not contain any textures or enhancements for the Village section (you can download the Village Texture Pack from here).
Chris and Albert will soon start working on the Island section in order to fully complete this massive HD project.
Those interested can download the Castle Texture Pack from here. Do note that the team suggests applying the 4GB patch tool which will alleviate random crashes you may have experienced (more info available here).