From past experience, a very slow boot-up could be hardware related (motherboard, memory, etc.) - but because it is happening on all of your pc's it has to be something common to all of them. There has been a lot of chatter lately about hackers gaining access to Internet routers. If you're using the cable company modem/router, then that is probably not the issue though, as they utilize multiple firewalls. If you're using your own modem, and/or router, then it would be worth checking into.
Another reason for very slow boot-up could be a trojan virus residing in the Master Boot Record (MBR). But, for that to happen on all of your pc's, they would've had to have a common denominator - something shared amongst all of them (e.g. flash drive, backup drive, networked together sharing resources, etc.). Also, if a cell phone is infected with a virus, and connect's to the computer, then the virus can migrate to the PC. MBR trojans can be difficult to eliminate, because they load before Windows, or antivirus software loads. Windows Antivirus has a scan setting that reboot's the PC and scans the hard drive before all of Windows loads - I would probably try that first. It may not be able to detect a MBR trojan though. To scan the MBR you would need to boot from USB or optical drive with a bootable virus scanner.
Without having "hand's on" the PC, I am only offering possibilities of what could be the issue(s). If you have a computer repair shop that you trust, you may want to just take one of them and see if they can figure it out.
•
News 
Market Data 
Discover 
