problem with resolution

[raja.genupula]

you can install gedit if you want with

sudo apt-get install gedit

[DragonGirl123]

I see. You are on Lubuntu, that means your text editor is leafpad (or mousepad, dunno), not gedit. Try:

gksudo leafpad /etc/default/grub

it said premission denied.

[pogopuschel]

Can you please copy and post the whole terminal output, means, the command you gave and the "answer"

[DragonGirl123]

do you mean to the command /etc/default/grub ? the answer i got is that bash: /etc/default/grub : Permission denied.

[pogopuschel]

/etc/default/grub is a path, not a command. Thats why I wanted you to copy,paste and post the whole terminal output here using code tags:
to ensure you give the right commands. "Permission denied" cannot be a valid answer when using sudo/gksudo, as long your user belongs to the sudoers group, which is default in Ubuntu.

[DragonGirl123]

oh sorry ,what do i have to type in the terminal? im little bit confused ,and sorry for my nooby linux skill

[pogopuschel]

Np, its absolute beginner section. I want you to copy& paste the command, not to type.
Paste into the terminal:

gksudo leafpad /etc/default/grub

hit enter and paste the whole terminal content please.

[DragonGirl123]

well it opened a new thingy ,thats called grub,do i now remove the nomodeset? also a picture about it http://postimg.org/image/4ny86ff97/

[pogopuschel]

Yes, remove it. Make it look like
GRUB_CMDLINE_LINUX=""
then close the file saving the changes. When closed, run:

sudo update-grub

Then reboot

[DragonGirl123]

sorry for the long time it took me to reply. Yay everything works now