This application receives one command line argument which is a path to a dirrectory. Then this directory and all subdirectories are seached for *.vtf files. Each .vtf file is checked for its version. If version is 7.5 it will be changed to 7.4. This is achieved by reading 8 byte in a .vtf file and checking if this byte is equal to 5, if yes, it is overwritten to be 4. This works because 7.5 is backwards compatible with 7.4. Meaning games that read 7.4 can also read 7.5. But some games(HL2) skip 7.5 only because version. Practical use of this app was to convert Alien Swarm textures to use them in HL2 mod.