USB DEVICE NOT RECONGIZED ??????

Hello


I have a toshiba laptop a135 s2386 which was really slow 512 MB RAM so,i tried changing the ram but the rams i bought didn't work. After changing the RAM within 24 hours the USB DEVICE PROBELM PURSUIT.


I tried all kind of things but did'nt work fully yet

1.Registry hack
2.unplug and plug power with removing the battery
3.reinstalling and install the drivers in safe mode
4.drivers update
5.delete infache.1
6.window update
7.System restore

I tried the registry hack and it worked but only 5 minutes. And again trying to fix problem by deleting infcache.1 7 times worked but unfortunately only 5 minutes again so , please help me


Still i can't solve the problem fully yet , it has been 3 months.