On Dell Precision T3500 running Windows 7 64 bit, we have been having irratic behavior such as, printers all disappear - when we try to print, message is something like "no printers installed" - and sometimes at start-up none of desktop icons will activate. We installed and ran cccleaner. Suspecting virus, we installed and ran Malwarebytes Anti-Malware which found and removed pup.datamngr but when we rebooted and ran Malwarebytes again the virus had returned. Now we are updating and running Malwarebytes each time we reboot. Last week we found a post topic on this forum discussing the same virus. We followd the steps, which included running Rkill, TDSSkiller and ESET Online Scan, and on reboot Malwarebytes found no virus but today printers disapeared again and when we ran Maalwarebytes we found pup.datamngr again. What do we do now?