isdone.dll - unarc.dll - Tried Everything

[YukonCanada]

Hi, so I have an Acer Nitro 5 with an i5 9300H / GTX 1050 3GB / 16gb Crucial RAM / 500GB 970 EVO Plus M.2 SSD / 1TB mech HDD / Windows 10 Home 1909 Dev Mode. I have been trying to install Tomb Raider Underworld and keep getting errors. ISDone.dll  An error occurred while unpacking: archive corrupted! Unarc.dll returned an error code: - 7 ERROR: archive data corrupted (decompression fails). Im quite sure the game files are not corrupted.  My drivers are all up to date. I have increased the virtual memory of my installation hard drive but didnt work. Even increased it to initial size-1000 max size-5000. Still a no go. Ran memory diagnostics , no problems. Tried installing it in safe mode, not working. Disabled AV and firewall, made exeptions but still nothing. Seems i dont have superfetch to turn off but seen it was renamed to sysmain, disabled it , did not work. Tried installing to other hard drives and still isnt working. I have tried re downloading the dll files , copied them to system32 and sysWOW64, tried to re register them in (admin) CMD but says  - The module "unarc.dll" was loaded but the entry point DllRegisterServer was not found. Make sure that "unarc.dll" is a valid DLL or OCX file and then try again. Ran sfc / scannow and DISM restorehealth commands with no luck.  I swear iv tried everything i can think of and this game crashes on install everytime. Any help would be very much appreciated. Thanks.

[mariushm]

Sounds like you're trying to install a cracked/pirated game.

ISDone is probably part of InnoSetup which is often used to make installers for ripped games (and legitimate software in general) and unarc is ARC archiver decompression library (arc is a free compressor like 7zip , known for achieving very high compression)

With such archives a single byte modified in the file will often cause the decompression to fail, but some antiviruses may also think unarc.dll is a virus or something like that.