This is most likely the remains of a malware infestation.
Before anything else, let's see if there's any malware left...
Please download and install Malwarebytes Anti-malware (free version) from http://www.malwarebytes.org/products/malwarebytes_free/ - UNtick 'Enable free trial of MBAM PRO' at the end of the installation - and update it, then run a full scan in your main account, and Quick scans in any other user accounts.
Delete everything it finds
My Computer
Computer type
Laptop
Computer Manufacturer/Model Number
Asus K52F or Lenovo B51-80
OS
Win 7 x64 Home Premium (and x86 VirtualBox VM)/Win10
CPU
i3 370M/i7 6500U
Motherboard
Asus/Lenovo
Memory
8GB - finally :)/8GB
Graphics Card(s)
it's an i3, dude!/dual Intel&nVidia
Sound Card
onboard
Monitor(s) Displays
15.6" built-in
Screen Resolution
1366x768/1920x1080
Hard Drives
750GB Seagate internal
Sundry external drives attached to other computers on the local network
1TB SSD on the Lenovo
PSU
n/a
Internet Speed
as much as I can get - usually on a dongle/phone, so <1MB/s
Are you still getting the 'pleasewait.exe' error?
If so, open MSCONFIG and look in the Startup listing, See if you can find it listed there. UNtick it, and post its details in your response, then reboot and see if the message has now gone.
My Computer
Computer type
Laptop
Computer Manufacturer/Model Number
Asus K52F or Lenovo B51-80
OS
Win 7 x64 Home Premium (and x86 VirtualBox VM)/Win10
CPU
i3 370M/i7 6500U
Motherboard
Asus/Lenovo
Memory
8GB - finally :)/8GB
Graphics Card(s)
it's an i3, dude!/dual Intel&nVidia
Sound Card
onboard
Monitor(s) Displays
15.6" built-in
Screen Resolution
1366x768/1920x1080
Hard Drives
750GB Seagate internal
Sundry external drives attached to other computers on the local network
1TB SSD on the Lenovo
PSU
n/a
Internet Speed
as much as I can get - usually on a dongle/phone, so <1MB/s