My PC is attacked by a Suspicious Script called "NTDETECT.exe" which is harming my PC's parformences. It's symtom is when i double click on my disk drives to open then cz of this script drives dont open. Instead my virus guard notify me about this script. It also denies me to unplug any removable drive. Can anybody tell me how I could get rid of this without formatting my HDD.
I would be grateful.

since you already know which file is the curlprit, i suggest uploading the file to www.virustotal.com for a check through the list of AV and identify it. From there you should be able to google a solution up based on the virus name.

and since you can online to write this to us, then i suggest u have ur pc scan online

here is the link http://housecall.trendmicro.com/