Can't start NiFi in win10

[#1]

I have installed NiFi but when I try to start it from the command line, with bin\run-nifi.bat, I get the following error:

Error: Could not find or load main class org.apache.nifi.bootstrap.RunNiFi

I have: 

Windows 10 SO 19042.867  

Java 8 1.8.0_291-b10

I tried doing it from administrator but it still doesn't work.... can anyone help me?

Thankyou!

[#2]

@MrWilkinson 

You may have a bad download?
Check the consistency of the contents of following folder:

<path to NiFi>/lib/bootstrap

[#3]

@MrWilkinson 

That could be a java-config issue 

Install JDK 8.0 64 bit.
Install Java to C:/java instead of C:/Program Files.
Recent Windows versions mark everything in C:\Program Files as read only.
Set the JAVA_HOME environment variable using the 8.3 style name conventions.
For example: C:\Program\jdk1.8.0.
Ensure JAVA_HOME is pointing to a 64-bit JRE/JDK.
Ensure your system meets the minimum memory requirement for Windows which is 4GB

Please share your install steps?