我已卸载Virtualbox 5.1，并在https://www.virtualbox.org/manual/ch02.html#install-linux-host之后安装了5.2
但是，尽管禁用了安全启动，但我得到：
vboxdrv.sh: failed: modprobe vboxnetflt failed. Please use 'dmesg' to find out why.
这似乎不是安全启动问题。
看着/sbin/rcvboxdrv：
我知道：
if ! $MODPROBE vboxnetflt > /dev/null 2>&1; then
failure "modprobe vboxnetflt failed. Please use 'dmesg' to find out why"
运行：
dmesg | grep vbox
尽管多次删除Virtualbox 5.1.38，我仍然看到它仍在加载错误的模块（即5.1.38）。
[ 11.070558] vboxdrv: loading out-of-tree module taints kernel.
[ 11.076066] vboxdrv: Found 8 processor cores
[ 11.096108] vboxdrv: TSC mode is Invariant, tentative frequency 2111999889 Hz
[ 11.096108] vboxdrv: Successfully loaded version 5.1.38_Ubuntu (interface 0x002a0000)
[ 133.468177] vboxdrv: Found 8 processor cores
[ 133.485226] vboxdrv: TSC mode is Invariant, tentative frequency 2111974740 Hz
[ 133.485229] vboxdrv: Successfully loaded version 5.1.38_Ubuntu (interface 0x002a0000)
[ 142.558097] vboxdrv: Found 8 processor cores
[ 142.577127] vboxdrv: TSC mode is Invariant, tentative frequency 2112016245 Hz
[ 142.577128] vboxdrv: Successfully loaded version 5.1.38_Ubuntu (interface 0x002a0000)
[ 233.707727] vboxdrv: Found 8 processor cores
[ 233.729829] vboxdrv: TSC mode is Invariant, tentative frequency 2111997273 Hz
[ 233.729831] vboxdrv: Successfully loaded version 5.1.38_Ubuntu (interface 0x002a0000)
[ 246.726812] vboxdrv: Found 8 processor cores
[ 246.749191] vboxdrv: TSC mode is Invariant, tentative frequency 2111995494 Hz
[ 246.749192] vboxdrv: Successfully loaded version 5.1.38_Ubuntu (interface 0x002a0000)
如何删除模块5.1.38_Ubuntu？