Can anyone help im not that hot with computers ,iam infected with the win32:srchassist-7{adw} i cant delete the virus when avast asks for confirmation to delete it wont allow me to .I dont have any problems with my keyboard and still cant delete. Theres no response and have had to turn my computer off / on manually then restart.Its driving me mad thanx.
Hi Nicola, and welcome to the forums. 
Firstly, disable avast!. Right click the blue (a)-ball near the time on the bottom right and click on “Stop On-Access Protection”
Secondly, try this online spyware scan: http://www.spywareguide.com/txt_onlinescan.html
Thirdly, if the second option does not work, download and run avast! External Control 1.6.105 from here: http://www.excessive-software.tk. Use the “Advanced file remover” feature to remove the offending file.
Fourthly download and run HijackThis from http://216.180.233.162/~merijn/files/HijackThis.exe and then post a log here for us to check.
Are you using Windows XP?
Can you schedule a boot-time scanning?
Start avast! > Right click the skin > Schedule a boot-time scanning
Select for scanning archives.
Boot.
Access denied means, generally, that the file is in use by another process (program) and cannot be repaired/cleaned/moved/handled by avast!
If a virus keeps coming back after you delete it, it’s most probably that System restore (folder) is infected.
Can you disable System Restore, boot then enable it again, run avast to be you’re clean?
How to Enable/Disable System restore on Windows ME: http://support.microsoft.com/default.aspx?scid=kb;en-us;Q264887
How to Enable/Disable System restore on Windows XP: http://support.microsoft.com/default.aspx?scid=kb;[LN];310405