Problem 1.
Trying to start Thunderbird. thunderbird page starts to load, then get app error:
'the instruction at 0x7c9106c3 referenced memory at 0x00a3e9be. the memory could not be written'.
Have removed and re-installed Thunderbird using newly downloaded version. no joy.
OS: windows xp prof w/service pack 2.
ran Avast antivirus sw It found instances of 4 trojans. trojan 'csrss.exe' had to be deleted by boot time scan. All trojans moved to chest.
Checked memory using ms diagnostic- no problems detected.
windows defender doesn't indicate any problem.
Used ms rootkit finder. no problems found.
network has 2 pc's/router no problem with other pc ISP- comcast. Browser- firefox v3.0

Problem 2: Firefox crashes intermittently and must be restarted.