If your Windows system is slow and you’ve already tried to clean up the autostarts you may have other issues. To do a global check on your system you can follow these steps:

1. Download Hiren’s Boot CD (list of software installed here)
2. Extract the zip file in a new folder (the zip contains many files)
3. Use the shipped CD creation tools BurnCDDC or use the excellent cdrtools Frontend going to CD image > Write image and choosing the Hiren’s.BootCD.x.x.iso file inside
4. Restart the PC with the CD in and boot from disk: after the boot a screen will be presented, usually you have to press a key like F12 to choose a boot device or press a key like F2 to go to BIOS and choose the boot order putting the DVD first
5. Choose Start Mini Windows XP and press Enter
6. After boot, you’ll see an interface similar to Windows XP: on Desktop click on My Computer to view if all drives are listed. Take a look at the space left on devices
7. Start > Programs > Check disk, insert the letter of the drive to check and then Enter
8. (Optional) After the disk check, you can also use other disk tools from Desktop > HBCD Menu > Programs > Hard disk tools if needed. Be careful, some tools can be dangerous and you have to know what you’re doing
9. Now that disk error are fixed, go to Desktop > HBCD Menu > Programs > Antivirus/Spyware and choose Avira or Malawarebytes’ Anti-Malaware
10. Choose the units and the scan mode and then run the tool
11. Repeat these steps with all tools you need in the Antivirus / Spyware section
12. Go to Desktop > HBCD Menu > Programs > Cleaners > CCleaner or ATF Cleaner and clean temporary files and entries from your system. Warning: personal data like browser saved password could be lost, choose the cleaning options carefully
13. On Desktop > HBCD Menu > Programs > Cleaners > MyUninstaller uninstall all application you don’t need
14. Check the space left on the disks on Desktop > My Computer. If little space is left on the main drive use Desktop > HBCD Menu > Programs > Cleaners > Windirstat to find big files (about Windirstat)
15. Now it’s time to look at the apps in autostart: go to Desktop > HBCD Menu > Programs > Startup tools > Autoruns: this is a Microsoft app that lists all application executed automatically. Look for suspicious entries and disable what you don’t need
16. You can explore other tools on this bootable CD depending on your needs

Tested with Hiren’s BootCD 15.2