My old desktop with XP Sp1 was attached by Virus and I had cleaned it but may accindental deleted some XP files. I am now having the following problems:-
1) I can'telete my internet messages where I used a thirty party domen service which used Javascrip to command for file deleting. I also can't go into 'Compose' page when using Yahoo Mail.
2) There was no Speaker Icon shown on the desktop but the audio feature works fine.
3) When a pendrive was plug in, the computer cannot recognise the equipment but when it was plugged in before the computer boot up, it work fine.
4) I suspect the Windows had been corrupted, how to repair it without reformate the harddrive ?

If you have a full Windows XP installation disk, you can try a repair of the installation.

See some detailed instructions here. Please note all the warnings!