Unable to install F-secure Antivirus of PC with Window XP, please advise.
Sorry for my reply.
How I can to understand: on current time -> all up-to-dated F-Secure solutions do not support Windows XP.
For F-Secure AV you also able to re-check requirements there:
Mainly this is based on next points:
--> This Windows already do not supported by Microsoft; and as result -there is too much "trouble-situation" to provide any proper security.
--> Also F-Secure AV with recent updates also do not able properly work with Windows XP (based already on using specific system-features, which work just with Windows Vista and later).
As additional information under Knowledgebase/How-To:
Also about Windows Vista, which also will be soon "not supported":