Patch 1.0.1 "can not replace existing file"

[pw2302]

Having picked up the 'Substance' in the chemical Lab, the game crashes wit an EXCEPTION_EXCESS_VIOLATION in unknown module.

I downloaded Patch 1.0.1. but the installer can not complete the installation as it "Can not replace existing file: Delete File Failed: Code 5 Access is denied." (see attached screen shot)

(I can not save at the Save point in the entrance to the Chemical area as the 'countdown' sequence is active).

How can I continue to the Examination area ? (Is there a save available ?)