Best antivirus for sp1 new install

Have always been in the habit of installing antivirus before doing windows updates on a clean install but having difficulty doing this with a windows 7 starter netbook. Bought on eBay and reset to factory settings via recovery partition (so not exactly a clean install). In this case as it’s an unknown netbook bought elsewhere wanted to make sure it was clean. Easy enough to install malwarebytes free via usb and that was all clear but had two attempts at downloading and installing two antivirus programs and difficulty installing (even with malwarebytes removed). Norton wouldn’t install. So tried Bitdefender trial which did install but won’t update. (I set browser opening page to about download site before connecting to internet). It only has ie9 so thought that may be the problem. So installed Firefox installer from usb. Still no joy. Bitdefender just says browser is out of date and install another one - which I have and it still won’t update (Firefox is set as default browser). I am wondering if it has a virus - possibly in the recovery partition. Suspect a virus because had one on another laptop (which av removed) but it’s one that spreads via the network. Can’t clean install starter and don’t have a home premium licence.

So think it’s too risky to leave it connected to the internet doing updates without av. Even though mwb is clear. Any other av that’s easy to install on sp1 I can try?

Never had a virus before but keep fixing up old netbooks and one of those had a virus that got in my usb stick (now binned). Luckily my av removed it when I plugged the usb stick into another laptop but it could have already spread before av found it. Have now immunised all my usb’s! But W7 starter is gla pain anyway and had glitches with it before - so could be it win’t Run modern av until updated. What do you think?

Thank you. After some googling, apparently it’s a common issue with the free trial version of Bitdefender. As for Norton it seems it has just updated to a new version which is also having instal issues. So will try something else.

An update. The reason Bitdefender woukdn’t update was because it had a phot captcha that needed verifying first and that dudn’t Display until net framework 3 was installed. Maybe same issue with Norton but also the inbuilt trend micro hadn’t uninstalled fully. Would have activated that but it said it was no longer supported. Norton still woukdn’t Install after net framework saying screen resolution too low (it’s a 10” netbook about 6 years old). Had a virus quarantined on another second hand laptop recently while this was turned on and just wanted to be sure it hadn’t been infected via the network. Been a total pain. Anyway have done scans with Kaspersky Rescue Disk, malwarebytes and Norton power. Eraser and all clean so it’s probably fine. Now just need to reset again and install mar and do the updates. Would have been quicker to do a clean install!

Interestingly mse says it’s better to have all updates done before installing mse!

Still unclear about recovery partitions though and whether the can be fully scanned. The virus was on a usb stick used to install Linux on an old pc that clearly was infected. Binned the usb stick.

MSE installed and windows updates going fine. Something weird though - when MSE was either updating or scanning, it got stuck for a while and the pc made 3 loud beeps - after that mse was unstuck and went along quickly. So is that a Windows update thing or an antivirus thing?