XP Vulnerabilities, post April 2014

See:

http://blogs.technet.com/b/security/archive/2013/08/15/the-risk-of-running-windows-xp-after-support-ends.aspx

Example:

FILE SHARES ISSUES

And other discussion, of Windows XP connecting to Windows 7 shares
http://forums.whirlpool.net.au/archive/2174686


And this on changing Lanman parameters in XP (hint set to 8 F's)
http://support.microsoft.com/kb/297684

And for Windows 7 shares or name dropping:
http://www.sevenforums.com/network-sharing/229734-windows-xp-computers-disconnect-shared-drives-windows-7-comp.html

• \CurrentControlSet\Services\lanmanserver\parameters\size
  Your choices for this registry key are 1,2 and 3.
  1 = Minimize Memory Used
  2 = Balance
  3 = Maximize Throughput for File Sharing and Maximize Throughput for Network Applications
  
  Be sure to set this to (3). By default it is configured to 1.
• \SYSTEM\CurrentControlSet\Control\Session Manager\Memory
  Management\LargeSystemCache
      By default this value is probably set to “0” and needs to be changed to “1”