Instruct: Classify Amazon reviews into positive or negative sentiment
Query: WARNING -- Major issues with BEFCMU 10 and Windows XP

After purchasing this modem I started to have an annoying problem where my PC would spotaneously restart in the middle of working on the internet. I contacted Linksys technical support, and they refused to admit that the problem traced to their product. After spending many hours with the Microsoft technical support help desk, we definitively isolated that problem to BEFCMU10.sys -- the software that came with this modem.DO NOT PURCHASE THIS MODEM IF YOU PLAN TO RUN WINDOWS XP OR UPGRADE TO IT AT A LATER DATE.