Heres a method to preview the movie by downloading only the first part.
To preview .mpg .wmv .avi .mp3 files -
Things you need -
1. Winrar Archiver
2. Password for the RAR Archive, if it is password protected
3. A Media Player like Winamp, WMP..............
How to do it -
Lets assume that you want to preview a movie that has been converted into 7 RAR Archives named - claudia_ferrari_shq.part1.rar, claudia_ferrari_shq.part2.rar, .............., claudia_ferrari_shq.part7.rar.
And lets say you have downloaded claudia_ferrari_shq.part1.rar and want to preview the move inside it. (Note for this to work you must download the first part. It doesnt matter if you download any number of parts as long as they are in order, ie. dont download the last part first).
Now open the first part with Winrar. And click on Extract To button.

Now comes the important part DONT FORGRET TO CHECK THE Keep broken files BOX AS SHOWN IN PICTURE


You can either enter a custom address to save the clip in or you can continue with the default address, like I did. Click Extract. If the file is password protected you will be prompted to enter the password, in this case enter the password and click ok. If you downloaded more than one archive (in this case I have downloaded 3 parts - claudia_ferrari_shq.part1.rar, claudia_ferrari_shq.part2.rar, claudia_ferrari_shq.part3.rar) you will get the following message -

Click Process All files in all volumes from the current, to extract files from all the downloaded parts. After this you will be able to see the extraction screen -

After the files from the parts have been ectracted you will prompted to give the path for the
next part.

Now click Cancel. On doing this an error window will pop-up.

Click Close.
Now go to the pathname which you initially gave, while extracting the file.

A new folder will have been created there.Open it.

now use vlc to view dat part