Scan virus from Dos
There are many cases in which we can not remove virus totally in Windows enviroment 
so in that cases I usually scan & remove virus from Dos.
All I have to do is:
1. Making a bootable floppy disk or USB or CD or Dos boot menu [ in case you made it when install Windows] – whatever can help you boot and get a Dos enviroment.
2. Go to: ftp://ftp.nai.com/pub/antivirus/superdat/intel/ and then download sdatxxxx.exe [xxxx is the version ]
3. After downloading, extract it to a folder [choose a simple name so you can easy to type quickly ] . For example: anti
4. Booting, get into Dos enviroment then use cd command to reach the folder you name as step 3. For example: cd anti
5. …anti> scan.exe [type scan.exe to let the program start -- in this tut I use Mcafee]
6. scan and remove virus!
Now you get ur solution, but it’s important to use a good anti-virus app to protect ur comp after that. And remember to keep it up to date!
thanks for this tip. i have a win7 crash where it will boot to splash screen, but not to login, this happens in safe mode as well. i have system restore turned off, and system repair will not help fix. so i choose to run some scans on the system.
i appreciate the tut!