My scanner, a Metrologic MS9520 was being used at a library and because of the recent flooding we had to move it to another location, now we are trying to use it with another computer and when we put a barcode underneath it a green light turns on but it isn't scanning. Is there special software or some other solution so we can start scanning?

SOURCE: Metrologic barcode scanner - laser is a dot not a line

This would be a fault with the scan engine. The dot is created when the mirror inside of the scan engine is not oscillating. The best solution is to have the device repaired, hopefully your scanner is still under warranty, or to purchase a replacement. /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} @page Section1 {size:612.0pt 792.0pt; margin:72.0pt 90.0pt 72.0pt 90.0pt; mso-header-margin:35.4pt; mso-footer-margin:35.4pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;}

SOURCE: Microsoft Metrologic MS9520 Voyager Barcode Scanner problem

If it is using the MX009 USB Cable it wont scan with the standard configuration. You will need extra configs such as enable Rs-232 Mode, Enable Xon/Xoff handshaking etc..
These can be found on the www.Metrologic.com website which will divert you to Honeywell website

SOURCE: We are using a Metrologic MS9520 (keyboard wedge)

What I would first is to bring the barcode scanner back to factory defaults. To do this you will need the manual that came with the scanner, on the first page is a bar code that say "enter/exit configuration mode" scan that first and you will hear three beeps, then scan the bar code for "recall defaults" and rescan the bar code to "enter/exit configuration mode" then retry using your scanner, if this does not work bring up "notepad" on your computer and try to scan any bar code form any retail item. This should scan, if it does net then it could be a defective scanner. See page 2 on the manual link

http://www.posguys.com/download/voyagerprogramming.pdf