You're likely facing blank screens in multiple browsers because Windows XP is unable to support the TLS/SSL protocols in use currently. TLS 1.0/1.1 and SSL v2/v3 have been deprecated in Windows Server environments and this is likely what XP requires. You may be able to find a process to implement support for the newer versions in the existing XP environment, but your best bet is to get those outdated clients up to date.
Kyle Kerst
System/Network Administrator
SmarterTools Inc.
(877) 357-6278
www.smartertools.com