Question: I'm sort of new to all this, and am not quite sure what I did. I somehow managed to delete the boot menu from my computer, so when it starts it automatically goes into Ubuntu. I got the boot menu back using boot-repair, but now Windows 7 isn't showing up as an option in the menu. Can anyone explain how to fix this and make it an option again? 

UPDATE: I've been trying to figure out what I did wrong, and based on other things I read it looks like there's supposed to be a second boot partition for windows and that is what I accidentally deleted somehow. So now grub does not recognize that windows is there. How do I fix that? 

<http://paste.ubuntu.com/12073785/>

<http://paste.ubuntu.com/12073797/>

Answer: 
That's extremely easy if you use the following set-up:

1. Use your existing bootable USB stick to install Ubuntu on an [SLC USB stick](https://en.wikipedia.org/wiki/Single-level_cell#Single-level_cell) (USB 3.0 preferred if your hardware supports it) Just a normal install, *treating the USB stick as an SSD.*

**Why?** The SLCs are twice as expensive as the [MLCs](https://en.wikipedia.org/wiki/Multi-level_cell) but they are 4 times faster and last 8\* longer! *So they really are small SSDs on a stick!*
2. Reboot from the USB and optimize the system and treat the USB stick as a small SSD, so:

In your `/etc/sysctl.conf` add:

```
# Fabby: change the "swappiness" to 10 to prevent swapping as much as possible
# to not wear out the USB stick as the Ubuntu default is optimized for a server.
# 10 to balance with vfs_cache_pressure
vm.swappiness = 10

# Fabby: Lower vfs_cache_pressure to 75% 
# (once cached, probably not immediately needed any more)
#
# This percentage value controls the tendency of the kernel to reclaim
# the memory which is used for caching of directory and inode objects.
#
# At the default value of vfs_cache_pressure=100 the kernel will attempt to
# reclaim dentries and inodes at a "fair" rate with respect to pagecache and
# swapcache reclaim.  Decreasing vfs_cache_pressure causes the kernel to prefer
# to retain dentry and inode caches.
vm.vfs_cache_pressure = 75

# Fabby: Good to improve sequential reads (stop stuttering in movie play)
# Can also be implemented per disk using udev rules
vm.max-readahead=2048
vm.min-readahead=1024

```

In your `/etc/fstab` add the **bold paramaters** to your boot USB line. (It'll probably be `sdc` or `sdd`. The below is an example, use UID if possible) 

`/dev/sdc / ext4 defaults,**noatime,discard**,errors=remount-ro 0 1`

Done! :-)
=========

For the record: I have a 16GB USB 2.0 SLC stick just like this (more then enough for my use-case and not too expensive and it's about 5 years old now and still running!)
1. if you created a boot usb everything will be deleted after shut down... there is one program for windows <http://www.linuxliveusb.com/> that i use on other peoples computer if i do not have a live usb on hand.
2. if you boot from a CD for example and then install Ubuntu on the usb then files will be saved please remember usb speeds will affect the OS
3. and YES the information its store temporary on the RAM memory when you boot a live usb