[Sisupoika]

Potresti incollare un log di Hijackthis, che e' ormai prassi da queste parti

Cmq puo' darsi non si tratti di virus.
Prova a scaricarti TweakUI, nella sezione "Desktop" puoi provare a ripristinare l'icona del Recycle Bin.
Vedi se poi ti scompare di nuovo.

In alternativa, copia questa roba in un file con estensione .reg, tasto destro su di esso -> Merge.

Ti ripristina il cestino cosi' com'e' dopo l'installazione di Windows, ricreando tutte le sue impostazioni.

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Desktop\NameSpace\{645FF040-5081-101B-9F08-00AA002F954E}]
@="Recycle Bin"

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{645FF040-5081-101B-9F08-00AA002F954E}]
@="Recycle Bin"
"InfoTip"=hex(2):40,00,25,00,53,00,79,00,73,00,74,00,65,00,6d,00,52,00,6f,00,\
  6f,00,74,00,25,00,5c,00,73,00,79,00,73,00,74,00,65,00,6d,00,33,00,32,00,5c,\
  00,53,00,48,00,45,00,4c,00,4c,00,33,00,32,00,2e,00,64,00,6c,00,6c,00,2c,00,\
  2d,00,32,00,32,00,39,00,31,00,35,00,00,00
"SortOrderIndex"=dword:00000060
"IntroText"=hex(2):40,00,25,00,53,00,79,00,73,00,74,00,65,00,6d,00,52,00,6f,00,\
  6f,00,74,00,25,00,5c,00,73,00,79,00,73,00,74,00,65,00,6d,00,33,00,32,00,5c,\
  00,53,00,48,00,45,00,4c,00,4c,00,33,00,32,00,2e,00,64,00,6c,00,6c,00,2c,00,\
  2d,00,33,00,31,00,37,00,34,00,38,00,00,00
"LocalizedString"=hex(2):40,00,25,00,53,00,79,00,73,00,74,00,65,00,6d,00,52,00,\
  6f,00,6f,00,74,00,25,00,5c,00,73,00,79,00,73,00,74,00,65,00,6d,00,33,00,32,\
  00,5c,00,53,00,48,00,45,00,4c,00,4c,00,33,00,32,00,2e,00,64,00,6c,00,6c,00,\
  2c,00,2d,00,38,00,39,00,36,00,34,00,00,00

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{645FF040-5081-101B-9F08-00AA002F954E}\DefaultIcon]
@=hex(2):25,00,53,00,79,00,73,00,74,00,65,00,6d,00,52,00,6f,00,6f,00,74,00,25,\
  00,5c,00,53,00,79,00,73,00,74,00,65,00,6d,00,33,00,32,00,5c,00,73,00,68,00,\
  65,00,6c,00,6c,00,33,00,32,00,2e,00,64,00,6c,00,6c,00,2c,00,33,00,31,00,00,\
  00
"Empty"=hex(2):25,00,53,00,79,00,73,00,74,00,65,00,6d,00,52,00,6f,00,6f,00,74,\
  00,25,00,5c,00,53,00,79,00,73,00,74,00,65,00,6d,00,33,00,32,00,5c,00,73,00,\
  68,00,65,00,6c,00,6c,00,33,00,32,00,2e,00,64,00,6c,00,6c,00,2c,00,33,00,31,\
  00,00,00
"Full"=hex(2):25,00,53,00,79,00,73,00,74,00,65,00,6d,00,52,00,6f,00,6f,00,74,\
  00,25,00,5c,00,53,00,79,00,73,00,74,00,65,00,6d,00,33,00,32,00,5c,00,73,00,\
  68,00,65,00,6c,00,6c,00,33,00,32,00,2e,00,64,00,6c,00,6c,00,2c,00,33,00,32,\
  00,00,00

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{645FF040-5081-101B-9F08-00AA002F954E}\InProcServer32]
@="shell32.dll"
"ThreadingModel"="Apartment"

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{645FF040-5081-101B-9F08-00AA002F954E}\shellex]

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{645FF040-5081-101B-9F08-00AA002F954E}\shellex\ContextMenuHandlers]

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{645FF040-5081-101B-9F08-00AA002F954E}\shellex\ContextMenuHandlers\{645FF040-5081-101B-9F08-00AA002F954E}]

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{645FF040-5081-101B-9F08-00AA002F954E}\shellex\PropertySheetHandlers]

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{645FF040-5081-101B-9F08-00AA002F954E}\shellex\PropertySheetHandlers\{645FF040-5081-101B-9F08-00AA002F954E}]

[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{645FF040-5081-101B-9F08-00AA002F954E}\ShellFolder]
"Attributes"=hex:40,01,00,20
"CallForAttributes"=dword:00000040