I have just started working with a new company and they have a master drawing with all the blocks they need for their detailed drawings. Problem is the person who created this simply made blocks, I want to have these done as WBLOCKS and saved in a block library. Is there an easy way to take the blocks in the drawing and have them saved in my block library? and  For example we have a screw and bolt block used 100 times in the drawing and I were to re-create my block using WBLOCK would I have to reinsert each one again? Hope this question makes sense

Task: Create a WBLOCK from an existing block in a drawing
On the command line, enter wblock. In the Write Block dialog box, under Source, click Block. Select the block you want from the drop-down list. Under Destination, in the File Name box, enter the file name for the WBLOCK. In the Location box, enter the location where you want to save the WBLOCK (new drawing file). Click OK to create the new drawing.

Thank you, I just noticed that option and was about to cancel my question.I do have one more question, if I do that does that mean that if I have multiple copies of that block will they all now be associated with the WBLOCK I created? So if I made a change to my block will all of them update? 

I believe they should but the only way to know for sure is test it. 

Hello MiriamO and John.
I have tested John's procedure because I wanted to be sure that the file created didn't include the block itself so it could lead to the impossibility of inserting that same block in an other drawing and it's OK because the new file created includes only the entities of the block and not the constituted block.
In explorating that particular file I found that there was no unities on that file unlike all my files.
Are there also others problems to do this procedure with already constituted blocks ( that is really interresting anyway ) ?

Not a big problem.Use the RENAME command and rename the old blocks to the new name.

Awesome, thank you

[QUOTE=MiriamO]
I have just started working with a new company and they have a master drawing with all the blocks they need for their detailed drawings. Problem is the person who created this simply made blocks, I want to have these done as WBLOCKS and saved in a block library. ... [/QUOTE]
I would just use the AutoCAD Design Center [ADC command, or Ctrl+2] to bring Blocks out of the master drawing.  That spares you the need to have separate .dwg files for each one, and to go through the procedure of Wblocking them all out of that drawing.  You can have ADC auto-retract over to the edge, and when you want another Block out of the same source drawing, just hover over that edge thingie and it will pop out again.

[QUOTE=MiriamO] .... if I do that does that mean that if I have multiple copies of that block will they all now be associated with the WBLOCK I created? So if I made a change to my block will all of them update? [/QUOTE]
If you have them as separate drawing files, and you XREF them rather than INSERT them, when you change the source drawing they will all be automatically updated in every drawing they're used in, the next time it's opened.If you get them from the master drawing using ADC, if you've altered the definition of a Block in the master drawing, right-click on its name in ADC and you can choose the "Insert and Redefine" option, which will update all Insertions of that Block in the current drawing.  You would need to do the same separately in every drawing you want that Block definition updated in.