Yes, but you said you installed a drive you had and booted it about 12 times and then switched the jumpers on the old one and installed it.. Example: It can take a few kick ups before a virus on a drive that was removed re-installs itself. It has to re-infect the new drive main root directory by installing itself on the main drive, then update the registry and on the last boot up it does the dirty deed.. This can be a one quick step or slow process to avoid detection.. I had one on the kids computer that we figure was installed from a web site that would not even let us get passed the BIOS start up on the Hard Drive.. Sneaky Basturd...