I have been trying to correct this problem for several months now and read through dozens of posts and tried dozens of solutions and I still cant figure it out. I have Windows 7 Ultimate home network with (1) Imac, and 4 PCs connected. The iMac can see the all PC's and can share files on all computers and network drives. Three of the PC's can see the iMac and share files, printers, and external drives. However, one PC, which happens to be my main PC that I use for all my work can see the iMac under network but when I try to connect to it, instead of getting the Username and Password prompt that the other computers get, receives the Windows network error "Windows cannot access \\IMAC and the error details say "0x80070035". Most of the fixes I read revolved around changing network security settings in Windows administration. Currently all (4) PC's have LAN Manager authentication level set to "Send LM & NTLM responses" & Min session security for NTLM set at "require 128-bit encryption". Regardless of what you read I know these settings work because, of course, (3) of the 4 PC's exchange files and hardware with no problem. All other security settings in local polices are set the same on all machines as well. - Compared adapter settings and network sharing options and they are all the same - All PC's have the same antivirus program - All are set to the same home group - I do not run any firewalls on any of the computers - All local security settings seem to be set identical on all machines. - I am able to ping the iMac from the PC in question with no problem either. Can anyone think of anything else to check that would keep this one PC from accessing the iMac? (this driving me NUTS!) Thanks you for any help!