One of the printers, a HP OfficeJet 6100, is connected to this Dell Precision M6600 laptop via USB. The other printer is a HP Color LaserJet CP4025dn and is connected via network cable. I have uninstalled both of them and then downloaded their drives from HP and re-installed them. The CP4025 is working now, but the 6100 is not.
I've had to troubleshoot and re-install printers on this laptop quite often. About 2 or 3 times a month. Have even replaced some printers for the same laptop. Twice, in the past 4 months. So, I decided to delete all printer drivers, before reinstalling the 2 currently used printers, for the laptop. I deleted all printers from Printers and Devices. I then went into print servers and deleted and uninstalled the printer drivers. While reinstalling the current printers, I noticed that the old printers (not connected anymore) reappeared in printers and devices.
As at the time of this report, the CP4025 did not have an exclamation mark.
This is for Windows 7 Professional 64 bit.