Need to update new to me, used computer. Don't know if infected or not

[Odysseus]

We closed an office and I inherited an eMachines, 3-4 year old Win 7 Home computer that was used by the bookkeeper (who is a cautious sort/not given to surfing and downloading, etc) but was on an office network, and who knows which other person might be doing what online.

So I would like to run a malware scan in the safest possible way to see if it is clean, and if so, to run Win 7 updates.

The machine is at my home and is offline for safety. I have the signin password and can start the computer. see the desktop, etc.

I know a little about PC's, probably just enough to understand simple instructions and to know when to ask for further guidance if I get in over my head.

How would you suggest that I proceed. Thanks

 

[Alejandro85]

The normal procedure when you receive a used computer like this is pretty much the same, don't bother analyzing it. The normal, and in fact the only way to ensure having a clean computer is to do a clean install. Extract any data it might have left, backup it and reinstall Windows. This will ensure you have a known-good starting point.

This suggestion is pretty much the same as when you buy a used computer, transfer computer from an employee to another or a computer becomes infected. Since yon don't know (and have no way to know) what happened to it before, just play safe and reformat it, unless you 100% trust the previous owner.

 

[Odysseus]

Sound advice for sure! Thanks.

The data files are not likely to be needed, but probably should be preserved since they are business records. Is the safest way to do so just write them to DVD and attach a note that they should not be assumed to be malware free (in case the files are ever called for).

Then do an eMachines factory reset?

Edit: I haven't done this sort of thing in a long time, but remember that I failed to find all of the files worth keeping last time I did. I assume that most of the data that might be needed will be in the "User" folder, but there is QuickBooks on the machine. Will those files be in the User folder or elsewhere? (I am not sure what to look for)

 

[torchwood]

In that case make an image using Macrium Free.
Imaging with free Macrium - Windows 7 Help Forums

then perform the factory reset.

Roy

 

[Odysseus]

Thanks, but not familiar with this. The total space used on the eMachines is over 80Gb. Will all of this go into the image, and if so how to do this without risk from (possible) malware on the eMachine?