strange problem related to dual boot scenario

[davexnet]

Hi all,

had Windows XP installed for the longest time, it has been running clean, no issues.

 

Made some space on the hard drive and installed Windows 10 on a separate partition.

Windows 10 works fine.  However, in Windows XP, now booting from the Windows 10 boot menu,

I've been having some crashes on some of my regular apps such as avast anti-virus and Firefox. 

The crashes specify "exception - illegal operation"

 

However, I discovered if I boot from XP's boot loader directly, skipping Windows 10 loader,

the problems stop and XP runs well again, no crashes.

 

I'm looking for some suggestions or possibilities, of what could be going on.

Any idea's appreciated.