Whatever you do regarding the Linux partition, it won't cure the problem with the Grub error, because that is on the MBR. Since I doubt that you are trying to erase any sensitive data on the Linux partition, use the quickest method. Not certain about the first 3, but the DoD takes longer.
The MBR can be restored to either Grub, or to the Windows Boot Manager, but I will leave it to someone keener than myself to fill in the details.
So long as that Linux partition remains, it is not actually free space, even though it is available.
EDIT: Actually, you don't really need to wipe that partition at all, the formatting process when you reinstall Ubuntu should be more than adequate.
EDIT2: This kind of problem can be avoided by installing each OS on a separate drive.
EDIT3: Hopefully, the reinstallation of Ubuntu would automatically include W7 on the Grub loader as before, but I don't really trust this process or Grub, thus the reason for EDIT2.
The MBR can be restored to either Grub, or to the Windows Boot Manager, but I will leave it to someone keener than myself to fill in the details.
So long as that Linux partition remains, it is not actually free space, even though it is available.
EDIT: Actually, you don't really need to wipe that partition at all, the formatting process when you reinstall Ubuntu should be more than adequate.
EDIT2: This kind of problem can be avoided by installing each OS on a separate drive.
EDIT3: Hopefully, the reinstallation of Ubuntu would automatically include W7 on the Grub loader as before, but I don't really trust this process or Grub, thus the reason for EDIT2.
My Computer
- Computer Manufacturer/Model Number
- DIY
- OS
- W7x64 Pro, SuSe 12.1/** W7 x64 Pro, XP MCE
- CPU
- Phenom II 1090T w/Noctua NH-D14 /**4400+ X2 w/CM Hyper TX 3
- Motherboard
- ASRock 890FX Deluxe 4/**A8N-SLI
- Memory
- 2 x 2GB Patriot PGS34g1600LLKA/**4x1GB Corsair VS
- Graphics Card(s)
- EVGA GTX460 SC/**EVGA 8800GTS
- Sound Card
- Asus Xonar D2X/**Xonar D1
- Monitor(s) Displays
- Acer X233H, Dell E152FPc /**LG M237-WD
- Screen Resolution
- 1920x1080 & 1024x768/**1980x1080
- Hard Drives
- WDC 2TB, 1.5TB, 1TB, 500GB,Seagate 500GB , Maxtor 80GB /**500GB Seagate & WDC 1TB Black
- PSU
- CM RS600 w/ APC BX1000G/**Antec 500 TP w/ APC BX1000
- Case
- HAF922/**Antec 1040IIB
- Cooling
- 3x200mm, 1x140 and 1x120mm/**5x80mm fans
- Keyboard
- Logitech Media USB/**Saitek Eclipse
- Mouse
- Cordless Trackman Wheel/**Ditto
- Internet Speed
- 3.3Mbps
- Other Info
- SB 560 5.1 w/ Sennheiser RS140/**Creative T20 speakers, Dvico FusionHDTV7 Gold RT, Cisco E3000, HP 5510V AIO, Linksys E3000, Belkin F5U237 hub and **F5D8055 adapter
(** = 2nd rig)