1. Have your XP CD handy and run...
2. Parasite removal programs.
http://reviews.cnet.com/5208-6132-0.html?forumID=32&threadID=1313&start=0 notes the five scanning tools and removal tools that are fairly safe. If one does encounter an issue, its always been damage done by the MALWARE. The most common issue being Layered Service Provider replacement which you can use LSPFIX (Hint: use http://www.google.com to find).
The thread has follow on discussions about new links if you don't want to use Google to find an item.
PS. All the tools are free.
After having used the Windows XP fax capability without problems for two years, it recently became flaky. The fax monitor won't open when I try to send a message even though that option is checked. Sometimes the messages go and sometimes they don't. I had one to appear in the sent file that the recipient never received.
I uninstalled and reinstalled it but that didn't help.