Have some VMs running in ESXi HA cluster. All of them have same virtual hardware, same OS. Sometimes one of them hungs. It's always a random VM. I see a blue screen (wallpaper, NOT BSOD) on a console of hypervisor and nothing else. No any load on CPU, memory or disk is present. I can establish connection over telnet for port 3389, but can't connect over RDP. No any records in eventlog. After reset VM works properly.
VMs:
XP SP3, all security updates installed.
2 cores on CPU
1 GB memory.