>>>>>I think some virus or Trojan got into my computer and now I only see one drive C: whereas before I had drivers D: and E:. The drive C: only shows very little space left. When I run the Windows Security Essentials it says that it cannot clean the computer and recommends downloading the Standard System Sweeper from some site. Does this sound as legitimate?
>>>>
>>>>Long live Kaspersky! I burned the ISO image of Kaspersky 10 Boot clean up ti a CD and started my computer from this CD. Almost immediately when the scanning started it found Rootkit.Boot.Pihar C and I chose to Disinfect it. Then Kaspersky scanned the entire drive (took about 3 hours) but didn't find anything. After I restarted the computer my drives are back, visible. And - during the last 10 minutes - I can't hear the message from Avast that some malicious url has been stopped. I think I am going to either buy or download Kaspersky, pay for it and remove Windows Security Essentials and Avast.
>>>>I also need to find a good software to make an image of my drive, just in case. I will start a new thread on that.
>>>>Thank you all for your help!
>>>
>>>My husband got Kaspersky when he bought his new Asus laptop (he is not happy with it, BTW). I told him that I only heard bad things about Kaspesky and told him to not install it. Windows 8 comes with Windows Defender which looks like MS Security Essentials.
>>>
>>>I am not sure if he needs to install it after all.
>>
>>I am not clear if your husband is not happy with Asus or Kaspersky? If latter, why?
>
>No, just with the Asus as we didn't install Kaspersky (we do have the CD). He doesn't like certain behaviors - say, when he is looking at the PDF file and highlight some text and then make it bigger, the selection shifts. The scrollbar doesn't seem to show the actual position in the browsers. I think it's more the OS problem (Windows 8), but anyway, all these little things make his work not comfortable.

When I buy a new notebook I will choose Windows 7 Prof.