id summary reporter owner description type status component version resolution keywords cc guest host 6096 WinXP crashes @ boot if GuestAdditions are installed (SMP/IO-APIC - AMD cpu) BenDJ "on, uname -ri 2.6.31.8-0.1-desktop x86_64 cat /proc/cpuinfo | grep ""model name"" model name : AMD Phenom(tm) II X4 945 Processor i've installed, rpm -qa | grep -i virtualbox VirtualBox-3.1-3.1.2_56127_openSUSE111-1.x86_64 with VT-x enabled. i've installed WinXP Pro. the install goes fine, and the Guest (re)boots & functions normally. if I install Guest Additions, the GA install completes ok. But, when I reboot the Guest, it FAILs, dropping me to the SafeMode etc selection screen. I can boot into SafeMode, but can't ""Boot normally"" at this point. It's not the Guest that's crashing, but rather the GuestOS ... If I UNinstall GAs @ SafeMode desktop, thee reboot the machine, all's OK. If I first DISable VT-x, then repeat -- installing GAs -- then, at reboot, the Guest boots fine. Fully reproducible here. " defect closed guest smp VirtualBox 3.2.12 fixed Windows XP Guest Additions VT-x Windows Linux