Security issues, and nosey family members.

My father, sis, and I have the same brand laptop. They are pretty close to being the same models. I was the last to purchase mine, and I have the least experience among us, although I have come a long way, this past year. I thought that by having the same brand/ model, we could help each other..so far my sis's hard drive failed. My dad told me that he had purchased an external hard drive, because he supposedly needs it..he told me that he had to mail in his laptop to have the screen replaced. He then asked me if it would be alright to check his email on my computer. I agreed, and I volunteered to bring my laptop to his house..after all, he is my dad, right? I asked him to use my wireless connection, and he insisted on hooking up to his connection, etc. I began to think that maybe he was attempting to spy on me..Would it have been possible for him to install, or transfer anything from mine to his? I have nothing to hide, but would hate to have dad invading my privacy..I had installed good anti-virus security and spyware programs prior to this, and since..How can I check to see if this has happened? Thanks for the help.

 

Thanks for the help. You wrote: "And if he does not have the PC in his possession, he would have to have remote administration type software installed inorder to get access to your PC." - Does he install that software into his pc, or mine? I started using an administrative password on start up..will this foil any remote access attempts, or is using a password even needed? (I am the sole user). Thanks again..