system crash during game play & blue screen error after sleep

Hmm, I don't believe you ever mentioned anything about graphic issues. Anyways, just be aware you may be suffering two separate incidents with their own symptoms. You may have resolved some by switching the router to ethernet instead of USB, but these graphic issues of yours may well be caused by something entirely different.

Anyways, I'm at least glad to see one of my solutions (change USB to ethernet) worked for the most part. You can use older routers no problem for the most part, but when you intend to connect to them with USB, that can be troublesome. It's never preferred to use USB when you have ethernet cable as an option, as USB should only be a last ditch effort when you have no other alternative.

If you wish for us to help you with the graphics thing, I suggest you make another thread focusing on those problems instead. Thanks!

recently i found some unusual folders in one of my hdd partition.. a snap is added showng that files.. is these files are harmful?

Their random nature is very conspicuous, so that would be cause for concern. Your best bet is to run some virus scanner on these. Otherwise it's either garbage pushed out from some software, or it's previously legitimate folders that have got mucked up by a corrupt NTFS partition. Do both the virus scan as well as run scan disk on the drive to ensure everything's ok.

i had done virus scan & it reports everything s fine.. any way i deleted that folders using admin account.. i just wanted to know why those folders and it says it require system privilages to delete.. any way i managed to delete them.. thank you for your help..