I would not get this error description with a defect in the video card, even if such a defective memory GraKa could certainly cause all kinds of errors. Sounds more like a driver error or conflict, or for a service that blocks in the background the application. If it happens only in web applications (you had only TS, Firefox and Youtube above), it could also be that a port of any service, Trojans, incoming requests, naming the. is completely occupied. Look at times, whether during this time, a process 100% CPU utilization increases in demand and if so, what process this is. If the PC is not completely, you can do so simply look in Task Manager under Processes.