BleepingComputer.com: Bluetooth mouse could be detected but won't connect to my laptop

hey guys.

first of all, my laptop is DELL INSPIRON N5010.
(Windows 7 64-bit. System Language: Japanese)
my bluetooth mouse is, BUFFALO BSMLB04 SERIES.

i could use it before. in time, my laptop started to run slow.
i tried some registry cleaners i think
then i noticed i couldn't use my bluetooth mouse anymore.

it started to pop a message: *the bluetooth software is missing* if i wasn't mistaken.
kind of panic, i googled some random bluetooth software, installed it without checking if it is compatible with my laptop
then i got into a fatal error.
i keep on looping back in the start-up repair.
so, i chose to reinstall windows because i couldn't do anything anymore. *i haven't reformatted it because i don't have Windows 7 CD and the backups of my drivers*
it showed me some errors in USB port and in the bluetooth thingy.

now i could use my laptop.
i degrade my bluetooth software.
now, my laptop could detect the wireless mouse but won't connect with it.
*infinite spinning circles*

if you need more info, i'll try to provide it as much as i could.
need help.