I have a PC that takes forever to boot and shut down. There are no viruses, I defragmented the drive, Removed unnecessary startup files, Deleted the cookies etc... but nothing helped. I ran PC Check , first time it showed Core CPU failure. I blew the dust off of the cpu fans and again ran PC Check, now the CPU error disappeared and it shows CMOS Ram errors, intermittently. The CMOS settings are also lost. The HD tests passed. Does failing CMOS battery give booting problems? Or what else could it be? There are other problems also like not being able to write to CD and Outlook problems.